diff --git a/backend/app/services/paper_trading_service.py b/backend/app/services/paper_trading_service.py
index 2c0a15d..c7a5d5b 100644
--- a/backend/app/services/paper_trading_service.py
+++ b/backend/app/services/paper_trading_service.py
@@ -297,8 +297,11 @@ class PaperTradingService:
         # 确保不超过可用空间
         position_value = min(position_value, available_position_value)
 
+        # 修正浮点数精度问题，保留 2 位小数
+        position_value = round(position_value, 2)
+
         # 计算对应的保证金
-        margin = position_value / max_leverage
+        margin = round(position_value / max_leverage, 2)
 
         logger.info(f"动态仓位计算: {position_size} | 可用空间: ${available_position_value:,.0f} | "
                    f"目标仓位: ${position_value:,.0f} | 保证金: ${margin:,.0f}")
@@ -521,7 +524,9 @@ class PaperTradingService:
             else:
                 pnl_percent = ((db_order.filled_price - exit_price) / db_order.filled_price) * 100
 
-            pnl_amount = db_order.quantity * pnl_percent / 100
+            # 修正浮点数精度，先四舍五入百分比
+            pnl_percent = round(pnl_percent, 4)
+            pnl_amount = round(db_order.quantity * pnl_percent / 100, 2)
 
             # 计算持仓时间
             hold_duration = datetime.utcnow() - db_order.opened_at if db_order.opened_at else timedelta(0)
@@ -1371,9 +1376,9 @@ class PaperTradingService:
                 if close_percent is None or close_percent <= 0 or close_percent > 100:
                     return {'success': False, 'error': f'无效的平仓比例: {close_percent}'}
 
-                # 计算平仓数量
-                close_quantity = order.quantity * (close_percent / 100)
-                remaining_quantity = order.quantity - close_quantity
+                # 计算平仓数量（修正浮点数精度）
+                close_quantity = round(order.quantity * (close_percent / 100), 2)
+                remaining_quantity = round(order.quantity - close_quantity, 2)
 
                 if remaining_quantity < 10:  # 剩余数量太小，直接全部平仓
                     return self._close_order_llm(order, db, 'PARTIAL_CLOSE', '部分平仓后剩余过少，直接全部平仓')