diff --git a/app/gitea_client.py b/app/gitea_client.py
index c07bf1c..5c683e4 100644
--- a/app/gitea_client.py
+++ b/app/gitea_client.py
@@ -60,10 +60,11 @@ class GiteaClient:
             response.raise_for_status()
             return True, "PR 合并成功"
         except httpx.HTTPStatusError as e:
-            error_msg = f"HTTP {e.response.status_code}"
             if e.response.status_code == 405:
-                error_msg += ": PR 已经合并或已关闭"
-            elif e.response.status_code == 409:
+                # PR 已经被合并或关闭，视为成功（期望的结果已达成）
+                return True, "PR 已经被合并或关闭"
+            error_msg = f"HTTP {e.response.status_code}"
+            if e.response.status_code == 409:
                 error_msg += ": 存在合并冲突"
             elif e.response.status_code == 403:
                 error_msg += ": Token 权限不足"
diff --git a/app/main.py b/app/main.py
index c3dd92a..c3a3b67 100644
--- a/app/main.py
+++ b/app/main.py
@@ -354,7 +354,7 @@ async def approve_report(report_id: int, session: AsyncSession = Depends(get_ses
         gitea_client = GiteaClient()
         success, message = gitea_client.merge_pr_by_url(report.pr_url)
         if not success:
-            raise HTTPException(status_code=500, detail=f"合并 PR 失败: {message}")
+            raise HTTPException(status_code=502, detail=f"合并 PR 失败: {message}")
 
     # 更新报告状态
     report.status = LogStatus.FIXED