diff --git a/backend/app/api/v1/practice.py b/backend/app/api/v1/practice.py
index a8887f2..aa1e3a9 100644
--- a/backend/app/api/v1/practice.py
+++ b/backend/app/api/v1/practice.py
@@ -724,8 +724,15 @@ async def end_practice_session(
             new_badges = await badge_service.check_and_award_badges(current_user.id)
             
             await db.commit()
+            # 第二次commit后需要refresh，避免DetachedInstanceError
+            await db.refresh(session)
         except Exception as e:
             logger.warning(f"练习经验值/奖章处理失败: {str(e)}")
+            # 确保 session 仍然可用
+            try:
+                await db.refresh(session)
+            except Exception:
+                pass
         
         return ResponseModel(
             code=200,