diff --git a/qlib/backtest/__init__.py b/qlib/backtest/__init__.py
index 96941776c..a4c20f730 100644
--- a/qlib/backtest/__init__.py
+++ b/qlib/backtest/__init__.py
@@ -1,6 +1,7 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 import copy
+from typing import Union
 
 from .account import Account
 from .exchange import Exchange
@@ -91,17 +92,53 @@ def get_exchange(
         return init_instance_by_config(exchange, accept_types=Exchange)
 
 
-def get_strategy_executor(
-    start_time, end_time, strategy, executor, benchmark="SH000300", account=1e9, exchange_kwargs={}
-):
-    trade_account = Account(
-        init_cash=account,
-        benchmark_config={
+def create_account_instance(start_time, end_time, benchmark: str, account: float, pos_type: str="Position") -> Account:
+    """
+    # TODO: is very strange pass benchmark_config in the account(maybe for report)
+    # There should be a post-step to process the report.
+
+    Parameters
+    ----------
+    start_time :
+        start time of the benchmark
+    end_time :
+        end time of the benchmark
+    benchmark : str
+        the benchmark for reporting
+    account : Union[float, str]
+        information for describing how to creating the account
+        For `float`
+            Using Account with a normal position
+        For `str`:
+            Using account with a specific Position
+    """
+    kwargs = {
+        "init_cash": account,
+        "benchmark_config": {
             "benchmark": benchmark,
             "start_time": start_time,
             "end_time": end_time,
         },
-    )
+        "pos_type": pos_type
+    }
+    return Account(**kwargs)
+
+
+def get_strategy_executor(start_time,
+                          end_time,
+                          strategy: BaseStrategy,
+                          executor: BaseExecutor,
+                          benchmark: str = "SH000300",
+                          account: Union[float, str] = 1e9,
+                          exchange_kwargs: dict = {},
+                          pos_type: str = "Position",
+                          ):
+
+    trade_account = create_account_instance(start_time=start_time,
+                                            end_time=end_time,
+                                            benchmark=benchmark,
+                                            account=account,
+                                            pos_type=pos_type)
 
     exchange_kwargs = copy.copy(exchange_kwargs)
     if "start_time" not in exchange_kwargs:
@@ -117,19 +154,47 @@ def get_strategy_executor(
     return trade_strategy, trade_executor
 
 
-def backtest(start_time, end_time, strategy, executor, benchmark="SH000300", account=1e9, exchange_kwargs={}):
+def backtest(start_time,
+             end_time,
+             strategy,
+             executor,
+             benchmark="SH000300",
+             account=1e9,
+             exchange_kwargs={},
+             pos_type: str = "Position"):
 
     trade_strategy, trade_executor = get_strategy_executor(
-        start_time, end_time, strategy, executor, benchmark, account, exchange_kwargs
+        start_time,
+        end_time,
+        strategy,
+        executor,
+        benchmark,
+        account,
+        exchange_kwargs,
+        pos_type=pos_type,
     )
     report_dict, indicator_dict = backtest_loop(start_time, end_time, trade_strategy, trade_executor)
 
     return report_dict, indicator_dict
 
 
-def collect_data(start_time, end_time, strategy, executor, benchmark="SH000300", account=1e9, exchange_kwargs={}):
+def collect_data(start_time,
+                 end_time,
+                 strategy,
+                 executor,
+                 benchmark="SH000300",
+                 account=1e9,
+                 exchange_kwargs={},
+                 pos_type: str = "Position"):
 
     trade_strategy, trade_executor = get_strategy_executor(
-        start_time, end_time, strategy, executor, benchmark, account, exchange_kwargs
+        start_time,
+        end_time,
+        strategy,
+        executor,
+        benchmark,
+        account,
+        exchange_kwargs,
+        pos_type=pos_type,
     )
     yield from collect_data_loop(start_time, end_time, trade_strategy, trade_executor)
diff --git a/qlib/backtest/account.py b/qlib/backtest/account.py
index 85ca57fa5..be1c25f95 100644
--- a/qlib/backtest/account.py
+++ b/qlib/backtest/account.py
@@ -3,10 +3,11 @@
 
 
 import copy
+from qlib.utils import init_instance_by_config
 import warnings
 import pandas as pd
 
-from .position import Position
+from .position import BasePosition, InfPosition, Position
 from .report import Report, Indicator
 from .order import Order
 from .exchange import Exchange
@@ -62,22 +63,32 @@ class AccumulatedInfo:
 
 
 class Account:
-    def __init__(self, init_cash, freq: str = "day", benchmark_config: dict = {}):
+    def __init__(self, init_cash: float=1e9, freq: str = "day", benchmark_config: dict = {}, pos_type:str = "Position"):
+        self.pos_type = pos_type
         self.init_vars(init_cash, freq, benchmark_config)
 
     def init_vars(self, init_cash, freq: str, benchmark_config: dict):
 
         # init cash
         self.init_cash = init_cash
-        self.current = Position(cash=init_cash)
+        self.current: BasePosition = init_instance_by_config({
+            'class': self.pos_type,
+            'kwargs': {
+                "cash": init_cash
+            },
+            'model_path': "qlib.backtest.position",
+        })
         self.accum_info = AccumulatedInfo()
         self.reset(freq=freq, benchmark_config=benchmark_config, init_report=True)
 
     def reset_report(self, freq, benchmark_config):
+        # portfolio related metrics
         self.report = Report(freq, benchmark_config)
-        self.indicator = Indicator()
         self.positions = {}
 
+        # trading related matric(e.g. high-frequency trading)
+        self.indicator = Indicator()
+
     def reset(self, freq=None, benchmark_config=None, init_report=False):
         """reset freq and report of account
 
@@ -102,7 +113,7 @@ class Account:
         return self.positions
 
     def get_cash(self):
-        return self.current.position["cash"]
+        return self.current.get_cash()
 
     def _update_state_from_order(self, order, trade_val, cost, trade_price):
         # update turnover
@@ -124,6 +135,11 @@ class Account:
             self.accum_info.add_return_value(profit)  # note here do not consider cost
 
     def update_order(self, order, trade_val, cost, trade_price):
+        if self.current.skip_update():
+            # TODO: supporting polymorphism for account
+            # updating order for infinite position is meaningless
+            return
+
         # if stock is sold out, no stock price information in Position, then we should update account first, then update current position
         # if stock is bought, there is no stock in current position, update current, then update account
         # The cost will be substracted from the cash at last. So the trading logic can ignore the cost calculation
@@ -142,7 +158,8 @@ class Account:
     def update_bar_count(self):
         """at the end of the trading bar, update holding bar, count of stock"""
         # update holding day count
-        self.current.add_count_all(bar=self.freq)
+        if not self.current.skip_update():
+            self.current.add_count_all(bar=self.freq)
 
     def update_current(self, trade_start_time, trade_end_time, trade_exchange):
         """update current to make rtn consistent with earning at the end of bar"""
@@ -243,11 +260,14 @@ class Account:
         elif atomic is False and inner_order_indicators is None:
             raise ValueError("inner_order_indicators is necessary in unatomic executor")
 
-        self.update_bar_count()
-        self.update_current(trade_start_time, trade_end_time, trade_exchange)
         if generate_report:
+            # report is portfolio related analysis
+            # TODO:  `update_bar_count` and  `update_current` should placed in Position and be merged.
+            self.update_bar_count()
+            self.update_current(trade_start_time, trade_end_time, trade_exchange)
             self.update_report(trade_start_time, trade_end_time)
 
+        # indicator is trading (e.g. high-frequency order execution) related analysis
         self.indicator.clear()
 
         if atomic:
diff --git a/qlib/backtest/executor.py b/qlib/backtest/executor.py
index d86d5e25a..bc4831f32 100644
--- a/qlib/backtest/executor.py
+++ b/qlib/backtest/executor.py
@@ -282,7 +282,10 @@ class NestedExecutor(BaseExecutor):
                 self.inner_strategy.alter_decision(trade_decision)
 
             _inner_trade_decision = self.inner_strategy.generate_trade_decision(_inner_execute_result)
+
+            # NOTE: Trade Calendar will step forward in the follow line
             _inner_execute_result = yield from self.inner_executor.collect_data(trade_decision=_inner_trade_decision)
+
             execute_result.extend(_inner_execute_result)
             inner_order_indicators.append(self.inner_executor.get_trade_indicator().get_order_indicator)
 
diff --git a/qlib/backtest/position.py b/qlib/backtest/position.py
index 92b549063..6b021c913 100644
--- a/qlib/backtest/position.py
+++ b/qlib/backtest/position.py
@@ -4,30 +4,182 @@
 
 import copy
 import pathlib
+from typing import Dict, List
 import pandas as pd
 import numpy as np
 from .order import Order
 
-"""
-Position module
-"""
 
-"""
-current state of position
-a typical example is :{
-  <instrument_id>: {
-    'count': <how many days the security has been hold>,
-    'amount': <the amount of the security>,
-    'price': <the close price of security in the last trading day>,
-    'weight': <the security weight of total position value>,
-  },
-}
+class BasePosition:
+    """
+    The Position want to maintain the position like a dictionary
+    Please refer to the `Position` class for the position
+    """
+    def __init__(self, cash=0., *args, **kwargs) -> None:
+        pass
 
-"""
+    def skip_update(self) -> bool:
+        """
+        Should we skip updating operation for this position
+        For example, updating is meaningless for InfPosition
+
+        Returns
+        -------
+        bool:
+            should we skip the updating operator
+        """
+        return False
+
+    def update_order(self, order: Order, trade_val: float, cost: float, trade_price: float):
+        """
+        Parameters
+        ----------
+        order : Order
+            the order to update the position
+        trade_val : float
+            the trade value(money) of dealing results
+        cost : float
+            the trade cost of the dealing results
+        trade_price : float
+            the trade price of the dealing results
+        """
+        raise NotImplementedError(f"Please implement the `update_order` method")
+
+    def update_stock_price(self, stock_id, price: float):
+        """
+        Updating the latest price of the order
+        The useful when clearing balance at each bar end
+
+        Parameters
+        ----------
+        stock_id :
+            the id of the stock
+        price : float
+            the price to be updated
+        """
+        raise NotImplementedError(f"Please implement the `update stock price` method")
+
+    def calculate_stock_value(self) -> float:
+        """
+        calculate the value of the all assets except cash in the position
+
+        Returns
+        -------
+        float:
+            the value(money) of all the stock
+        """
+        raise NotImplementedError(f"Please implement the `calculate_stock_value` method")
+    def get_stock_list(self) -> List:
+        """
+        Get the list of stocks in the position.
+        """
+        raise NotImplementedError(f"Please implement the `get_stock_list` method")
+
+    def get_stock_price(self, code) -> float:
+        """
+        get the latest price of the stock
+
+        Parameters
+        ----------
+        code :
+            the code of the stock
+        """
+        raise NotImplementedError(f"Please implement the `get_stock_price` method")
+
+    def get_stock_amount(self, code) -> float:
+        """
+        get the amount of the stock
+
+        Parameters
+        ----------
+        code :
+            the code of the stock
+
+        Returns
+        -------
+        float:
+            the amount of the stock
+        """
+        raise NotImplementedError(f"Please implement the `get_stock_amount` method")
+
+    def get_cash(self) -> float:
+        """
+
+        Returns
+        -------
+        float:
+            the cash in position
+        """
+        raise NotImplementedError(f"Please implement the `get_cash` method")
+
+    def get_stock_amount_dict(self) -> Dict:
+        """
+        generate stock amount dict {stock_id : amount of stock}
+
+        Returns
+        -------
+        Dict:
+            {stock_id : amount of stock}
+        """
+        raise NotImplementedError(f"Please implement the `get_stock_amount_dict` method")
+
+    def get_stock_weight_dict(self, only_stock: bool=False) -> Dict:
+        """
+        generate stock weight dict {stock_id : value weight of stock in the position}
+        it is meaningful in the beginning or the end of each trade date
+
+        Parameters
+        ----------
+        only_stock : bool
+            If only_stock=True, the weight of each stock in total stock will be returned
+            If only_stock=False, the weight of each stock in total assets(stock + cash) will be returned
+
+        Returns
+        -------
+        Dict:
+            {stock_id : value weight of stock in the position}
+        """
+        raise NotImplementedError(f"Please implement the `get_stock_weight_dict` method")
+
+    def add_count_all(self, bar):
+        """
+        Will be called at the end of each bar on each level
+
+        Parameters
+        ----------
+        bar :
+            The level to be updated
+        """
+        raise NotImplementedError(f"Please implement the `add_count_all` method")
+
+    def update_weight_all(self):
+        """
+        Updating the position weight;
+
+        # TODO: this function is a little weird. The weight data in the position is in a wrong state after dealing order
+        # and before updating weight.
+
+        Parameters
+        ----------
+        bar :
+            The level to be updated
+        """
+        raise NotImplementedError(f"Please implement the `add_count_all` method")
 
 
-class Position:
-    """Position"""
+class Position(BasePosition):
+    """Position
+
+    current state of position
+    a typical example is :{
+      <instrument_id>: {
+        'count': <how many days the security has been hold>,
+        'amount': <the amount of the security>,
+        'price': <the close price of security in the last trading day>,
+        'weight': <the security weight of total position value>,
+      },
+    }
+    """
 
     def __init__(self, cash=0, position_dict={}, now_account_value=0):
         # NOTE: The position dict must be copied!!!
@@ -37,23 +189,35 @@ class Position:
         self.position["cash"] = cash
         self.position["now_account_value"] = now_account_value
 
-    def init_stock(self, stock_id, amount, price=None):
+    def _init_stock(self, stock_id, amount, price=None):
+        """
+        initialization the stock in current position
+
+        Parameters
+        ----------
+        stock_id :
+            the id of the stock
+        amount : float
+            the amount of the stock
+        price :
+             the price when buying the init stock
+        """
         self.position[stock_id] = {}
         self.position[stock_id]["amount"] = amount
         self.position[stock_id]["price"] = price
         self.position[stock_id]["weight"] = 0  # update the weight in the end of the trade date
 
-    def buy_stock(self, stock_id, trade_val, cost, trade_price):
+    def _buy_stock(self, stock_id, trade_val, cost, trade_price):
         trade_amount = trade_val / trade_price
         if stock_id not in self.position:
-            self.init_stock(stock_id=stock_id, amount=trade_amount, price=trade_price)
+            self._init_stock(stock_id=stock_id, amount=trade_amount, price=trade_price)
         else:
             # exist, add amount
             self.position[stock_id]["amount"] += trade_amount
 
         self.position["cash"] -= trade_val + cost
 
-    def sell_stock(self, stock_id, trade_val, cost, trade_price):
+    def _sell_stock(self, stock_id, trade_val, cost, trade_price):
         trade_amount = trade_val / trade_price
         if stock_id not in self.position:
             raise KeyError("{} not in current position".format(stock_id))
@@ -66,11 +230,11 @@ class Position:
                     "only have {} {}, require {}".format(self.position[stock_id]["amount"], stock_id, trade_amount)
                 )
             elif abs(self.position[stock_id]["amount"]) <= 1e-5:
-                self.del_stock(stock_id)
+                self._del_stock(stock_id)
 
         self.position["cash"] += trade_val - cost
 
-    def del_stock(self, stock_id):
+    def _del_stock(self, stock_id):
         del self.position[stock_id]
 
     def check_stock(self, stock_id):
@@ -80,10 +244,10 @@ class Position:
         # handle order, order is a order class, defined in exchange.py
         if order.direction == Order.BUY:
             # BUY
-            self.buy_stock(order.stock_id, trade_val, cost, trade_price)
+            self._buy_stock(order.stock_id, trade_val, cost, trade_price)
         elif order.direction == Order.SELL:
             # SELL
-            self.sell_stock(order.stock_id, trade_val, cost, trade_price)
+            self._sell_stock(order.stock_id, trade_val, cost, trade_price)
         else:
             raise NotImplementedError("do not support order direction {}".format(order.direction))
 
@@ -122,6 +286,7 @@ class Position:
         return self.position[code]["amount"]
 
     def get_stock_count(self, code, bar):
+        """the days the account has been hold, it may be used in some special strategies"""
         if f"count_{bar}" in self.position[code]:
             return self.position[code][f"count_{bar}"]
         else:
@@ -215,3 +380,55 @@ class Position:
         self.position = positions
         self.position["cash"] = cash
         self.position["now_account_value"] = now_account_value
+
+
+
+class InfPosition(BasePosition):
+    """
+    Position with infinite cash and amount.
+
+    This is useful for generating random orders.
+    """
+    def skip_update(self) -> bool:
+        """ Updating state is meaningless for InfPosition """
+        return True
+
+    def update_order(self, order: Order, trade_val: float, cost: float, trade_price: float):
+        pass
+
+    def update_stock_price(self, stock_id, price: float):
+        pass
+
+    def calculate_stock_value(self) -> float:
+        """
+        Returns
+        -------
+        float:
+            infinity stock value
+        """
+        return np.inf
+
+    def get_stock_list(self) -> List:
+        raise NotImplementedError(f"InfPosition doesn't support stock list position")
+
+    def get_stock_price(self, code) -> float:
+        """the price of the inf position is meaningless"""
+        return np.nan
+
+    def get_stock_amount(self, code) -> float:
+        return np.inf
+
+    def get_cash(self) -> float:
+        return np.inf
+
+    def get_stock_amount_dict(self) -> Dict:
+        raise NotImplementedError(f"InfPosition doesn't support get_stock_amount_dict")
+
+    def get_stock_weight_dict(self, only_stock: bool) -> Dict:
+        raise NotImplementedError(f"InfPosition doesn't support get_stock_weight_dict")
+
+    def add_count_all(self, bar):
+        raise NotImplementedError(f"InfPosition doesn't support get_stock_weight_dict")
+
+    def update_weight_all(self):
+        raise NotImplementedError(f"InfPosition doesn't support update_weight_all")
diff --git a/qlib/backtest/profit_attribution.py b/qlib/backtest/profit_attribution.py
index 7e1844a6f..05ee138cb 100644
--- a/qlib/backtest/profit_attribution.py
+++ b/qlib/backtest/profit_attribution.py
@@ -1,6 +1,8 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
-
+"""
+This module is not well maintained.
+"""
 
 import numpy as np
 import pandas as pd
diff --git a/qlib/backtest/report.py b/qlib/backtest/report.py
index a3bb0b10e..75b743694 100644
--- a/qlib/backtest/report.py
+++ b/qlib/backtest/report.py
@@ -17,9 +17,15 @@ from ..tests.config import CSI300_BENCH
 
 
 class Report:
-    # daily report of the account
-    # contain those followings: returns, costs turnovers, accounts, cash, bench, value
-    # update report
+    '''
+    Motivation:
+        Report is for supporting portfolio related metrics.
+
+    Implementation:
+        daily report of the account
+        contain those followings: returns, costs turnovers, accounts, cash, bench, value
+        update report
+    '''
     def __init__(self, freq: str = "day", benchmark_config: dict = {}):
         """
         Parameters
diff --git a/qlib/backtest/utils.py b/qlib/backtest/utils.py
index f524d09fe..85d88068a 100644
--- a/qlib/backtest/utils.py
+++ b/qlib/backtest/utils.py
@@ -1,6 +1,7 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 
+from qlib.backtest.order import Order
 from qlib.strategy.base import BaseStrategy
 from qlib.backtest.exchange import Exchange
 from qlib.backtest.account import Account
@@ -158,7 +159,7 @@ class BaseTradeDecision:
 
     def get_decision(self) -> List[object]:
         """
-        get the concrete decision of the order
+        get the **concrete decision**  (e.g. concrete decision)
         This will be called by the inner strategy
 
         Returns
@@ -173,13 +174,15 @@ class BaseTradeDecision:
         """
         raise NotImplementedError(f"This type of input is not supported")
 
-    NOT_AVAIL = 0
-    NO_UPDATE = 1
-    NEW_UPDATE = 2
-    def update(self, trade_step: int, trade_len: int) -> "BaseTradeDecison":
+    def update(self, trade_calendar: TradeCalendarManager) -> "BaseTradeDecison":
         """
         Be called at the **start** of each step
 
+        Parameters
+        ----------
+        trade_calendar : TradeCalendarManager
+            The calendar of the **inner strategy**!!!!!
+
         Returns
         -------
         None:
@@ -187,23 +190,28 @@ class BaseTradeDecision:
         BaseTradeDecison:
             New update, use new decision
         """
-        return self.strategy.update_trade_decision(self, trade_step, trade_len)
+        return self.strategy.update_trade_decision(self, trade_calendar)
 
     def get_range_limit(self) -> Tuple[int, int]:
         """
-        return the expected step range for limiting the dealing time of the order
+        return the expected step range for limiting the decision execution time
 
         Returns
         -------
         Tuple[int, int]:
 
-
         Raises
         ------
         NotImplementedError:
             If the decision can't provide a unified start and end
         """
-        raise NotImplementedError(f"This type of input is not supported")
+        raise NotImplementedError(f"Please implement the `func` method")
+
+
+class TradeDecisonWO(BaseTradeDecision):
+    def __init__(self, order_list: List[Order], strategy: BaseStrategy):
+        super().__init__(strategy)
+        self.order_list = order_list
 
 
 class TradeDecison(BaseTradeDecision):
@@ -316,6 +324,13 @@ class TradeDecison(BaseTradeDecision):
         elif not only_enable:
             return list(self.disable_dict.values())
 
-    def update(self, trade_step, trade_len):
-        """make the original strategy update the enabled status of orders."""
-        self.ori_strategy.update_trade_decision(self, trade_step, trade_len)
+    def update(self, trade_calendar: TradeCalendarManager):
+        """
+        make the original strategy update the enabled status of orders.
+
+        Parameters
+        ----------
+        trade_calendar : TradeCalendarManager
+            the trade calendar for sub strategy
+        """
+        self.ori_strategy.update_trade_decision(self, trade_calendar)
diff --git a/qlib/contrib/strategy/cost_control.py b/qlib/contrib/strategy/cost_control.py
index 88e35b2e4..b45c03ae9 100644
--- a/qlib/contrib/strategy/cost_control.py
+++ b/qlib/contrib/strategy/cost_control.py
@@ -1,5 +1,8 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
+"""
+This strategy is not well maintained
+"""
 
 
 from .order_generator import OrderGenWInteract
diff --git a/qlib/contrib/strategy/model_strategy.py b/qlib/contrib/strategy/model_strategy.py
index 679385043..71f9ee509 100644
--- a/qlib/contrib/strategy/model_strategy.py
+++ b/qlib/contrib/strategy/model_strategy.py
@@ -1,4 +1,5 @@
 import copy
+from qlib.backtest.position import Position
 import warnings
 import numpy as np
 import pandas as pd
@@ -328,6 +329,8 @@ class WeightStrategyBase(ModelStrategy):
         if pred_score is None:
             return []
         current_temp = copy.deepcopy(self.trade_position)
+        assert(isinstance(current_temp, Position))  # Avoid InfPosition
+
         target_weight_position = self.generate_target_weight_position(
             score=pred_score, current=current_temp, trade_start_time=trade_start_time, trade_end_time=trade_end_time
         )
diff --git a/qlib/contrib/strategy/rule_strategy.py b/qlib/contrib/strategy/rule_strategy.py
index ad3e06ce1..c0993f44e 100644
--- a/qlib/contrib/strategy/rule_strategy.py
+++ b/qlib/contrib/strategy/rule_strategy.py
@@ -76,8 +76,6 @@ class TWAPStrategy(BaseStrategy):
         trade_step = self.trade_calendar.get_trade_step()
         # get the total count of trading step
         trade_len = self.trade_calendar.get_trade_len()
-        # update outer trade decision
-        self.outer_trade_decision.update(trade_step, trade_len)
 
         # update the order amount
         if execute_result is not None:
@@ -204,8 +202,6 @@ class SBBStrategyBase(BaseStrategy):
         trade_step = self.trade_calendar.get_trade_step()
         # get the total count of trading step
         trade_len = self.trade_calendar.get_trade_len()
-        # update outer trade decision
-        self.outer_trade_decision.update(trade_step, trade_len)
 
         # update the order amount
         if execute_result is not None:
@@ -527,7 +523,7 @@ class ACStrategy(BaseStrategy):
         # get the total count of trading step
         trade_len = self.trade_calendar.get_trade_len()
         # update outer trade decision
-        self.outer_trade_decision.update(trade_step, trade_len)
+        self.outer_trade_decision.update(self.trade_calendar)
 
         # update the order amount
         if execute_result is not None:
@@ -602,7 +598,7 @@ class ACStrategy(BaseStrategy):
 class RandomOrderStrategy(BaseStrategy):
 
     def __init__(self,
-                 time_range: Tuple = ("9:30", "15:00"),  # left closed and right closed.
+                 time_range: Tuple = ("9:30", "15:00"),  # The range is closed on both left and right.
                  sample_ratio: float = 1.,
                  volume_ratio: float = 0.01,
                  market: str = "all",
@@ -614,6 +610,7 @@ class RandomOrderStrategy(BaseStrategy):
         time_range : Tuple
             the intra day time range of the orders
             the left and right is closed.
+            # TODO: this is a time_range level limitation. We'll implement a more detailed limitation later.
         sample_ratio : float
             the ratio of all orders are sampled
         volume_ratio : float
@@ -632,6 +629,4 @@ class RandomOrderStrategy(BaseStrategy):
         self.volume = D.features(D.instruments("market"), ["Mean($volume, 10)"], start_time=exch.start_time, end_time=exch.end_time)
 
     def generate_trade_decision(self, execute_result=None):
-
-
         return super().generate_trade_decision(execute_result=execute_result)
diff --git a/qlib/strategy/base.py b/qlib/strategy/base.py
index 6c8917658..f060ccdb7 100644
--- a/qlib/strategy/base.py
+++ b/qlib/strategy/base.py
@@ -7,7 +7,7 @@ from ..data.dataset import DatasetH
 from ..data.dataset.utils import convert_index_format
 from ..rl.interpreter import ActionInterpreter, StateInterpreter
 from ..utils import init_instance_by_config
-from ..backtest.utils import BaseTradeDecision, CommonInfrastructure, LevelInfrastructure, TradeDecison
+from ..backtest.utils import BaseTradeDecision, CommonInfrastructure, LevelInfrastructure, TradeCalendarManager, TradeDecison
 
 
 class BaseStrategy:
@@ -84,19 +84,23 @@ class BaseStrategy:
         """
         raise NotImplementedError("generate_trade_decision is not implemented!")
 
-    def update_trade_decision(self, trade_decison: BaseTradeDecision, trade_step: int, trade_len: int) -> BaseTradeDecision:
-        """update trade decision in each step of inner execution, this method enable all order
+    def update_trade_decision(self, trade_decison: BaseTradeDecision, trade_calendar: TradeCalendarManager) -> Union[BaseTradeDecision, None]:
+        """
+        update trade decision in each step of inner execution, this method enable all order
 
         Parameters
         ----------
         trade_decison : TradeDecison
             the trade decison that will be updated
+        trade_calendar : TradeCalendarManager
+            The calendar of the **inner strategy**!!!!!
+
         Returns
         -------
             BaseTradeDecision:
         """
-        if trade_step == 0:
-            trade_decison.enable(all_enable=True)
+        # default to return None, which indicates that the trade decision is not changed
+        return None
 
     def alter_outer_trade_decision(self, outer_trade_decision: BaseTradeDecision):
         """
@@ -108,6 +112,9 @@ class BaseStrategy:
         outer_trade_decision : BaseTradeDecision
             the decision updated by the outer strategy
         """
+
+        # default to reset the decision directly
+        # NOTE: normally, user should do something to the strategy due to the change of outer decision
         self.outer_trade_decision = outer_trade_decision