diff --git a/backend_api_python/app/services/trading_executor.py b/backend_api_python/app/services/trading_executor.py
index a663c39..8728933 100644
--- a/backend_api_python/app/services/trading_executor.py
+++ b/backend_api_python/app/services/trading_executor.py
@@ -708,7 +708,7 @@ class TradingExecutor:
                     # 2. 检查是否需要更新K线（每个K线周期更新一次，从API拉取）
                     # ============================================
                     if current_time - last_kline_update_time >= kline_update_interval:
-                        klines = self._fetch_latest_kline(symbol, timeframe, limit=500)
+                        klines = self._fetch_latest_kline(symbol, timeframe, limit=history_limit)
                         if klines and len(klines) >= 2:
                             df = self._klines_to_dataframe(klines)
                             if len(df) > 0: