diff --git a/ci.json b/ci.json
index 290a3f3586..3f2ce494b1 100644
--- a/ci.json
+++ b/ci.json
@@ -43,7 +43,7 @@
     }
   },
   "downgrade": {
-    "versions": "8.1,7.2,7.1,7.0"
+    "versions": "8.4,8.1,7.2,7.1,7.0"
   },
   "upload": {
     "bucket": "download",
diff --git a/module/common/model.php b/module/common/model.php
index d3dc7d1902..4ed79d0210 100644
--- a/module/common/model.php
+++ b/module/common/model.php
@@ -1143,6 +1143,7 @@ class commonModel extends model
         if(empty($maintenance)) return true;
 
         $maintenance = json_decode($maintenance);
+        if($this->app->moduleName == 'user' && $this->app->methodName == 'login') return true;
         if(!empty($this->app->user->admin)) return true;
 
         if(isset($maintenance->action) && in_array($maintenance->action, array('upgrade', 'downgrade', 'restore'))) helper::setStatus(503);
diff --git a/module/common/test/model/checkmaintenance.php b/module/common/test/model/checkmaintenance.php
new file mode 100644
index 0000000000..ce4ca68281
--- /dev/null
+++ b/module/common/test/model/checkmaintenance.php
@@ -0,0 +1,40 @@
+#!/usr/bin/env php
+<?php
+include dirname(__FILE__, 5) . '/test/lib/init.php';
+
+/**
+
+title=测试 commonModel::checkMaintenance();
+timeout=0
+cid=1
+
+- 检查是否处于维护状态 @0
+- 检查是否处于维护状态 @0
+- 检查是否处于维护状态 @0
+- 检查是否处于维护状态 @0
+- 检查是否处于维护状态 @0
+
+*/
+
+global $tester;
+$tester->loadModel('common');
+
+$app->moduleName = 'user';
+$app->methodName = 'login';
+r($tester->common->checkMaintenance()) && p() && e('1'); // 检查是否处于维护状态
+
+$app->moduleName = 'execution';
+$app->methodName = 'task';
+r($tester->common->checkMaintenance()) && p() && e('1'); // 检查是否处于维护状态
+
+$app->moduleName = 'program';
+$app->methodName = 'view';
+r($tester->common->checkMaintenance()) && p() && e('1'); // 检查是否处于维护状态
+
+$app->moduleName = 'bug';
+$app->methodName = 'view';
+r($tester->common->checkMaintenance()) && p() && e('1'); // 检查是否处于维护状态
+
+$app->moduleName = 'task';
+$app->methodName = 'view';
+r($tester->common->checkMaintenance()) && p() && e('1'); // 检查是否处于维护状态