diff --git a/src/Http/Middleware/CheckoutSite.php b/src/Http/Middleware/CheckoutSite.php
index 70627a73d5b3de06cdc4d4a17e327f0bbb7c3652..3605fe184969721b3a61a2414bb26a6062611092 100644
--- a/src/Http/Middleware/CheckoutSite.php
+++ b/src/Http/Middleware/CheckoutSite.php
@@ -20,6 +20,9 @@ namespace Discuz\Http\Middleware;
 
 use App\Common\ResponseCode;
 use App\Models\Group;
+use App\Models\GroupPaidUser;
+use App\Models\GroupUser;
+use App\Models\GroupUserMq;
 use App\Models\Invite;
 use App\Models\Order;
 use App\Repositories\UserRepository;
@@ -38,6 +41,9 @@ class CheckoutSite implements MiddlewareInterface
 {
     use AssertPermissionTrait;
 
+    const CACHE_GROUP_USER_TIME = 300;
+    const CACHE_GROUP_USER_MQS_TIME = 300;
+
     protected $app;
 
     protected $settings;
@@ -99,6 +105,7 @@ class CheckoutSite implements MiddlewareInterface
 //        }
         // $siteClose && $this->assertAdmin($actor);
         $this->checkPayMode($request, $actor);
+        $this->judgeGroupUser($actor);
         // 处理 付费模式 逻辑， 过期之后 加入待付费组
         if (!$actor->isAdmin() && $siteMode === 'pay' && ( Carbon::now()->gt($actor->expired_at) || $actor->isGuest() )) {
             if (!$this->getOrder($actor) && !$this->getInvite($actor)) {
@@ -164,4 +171,82 @@ class CheckoutSite implements MiddlewareInterface
             ->where('status', Invite::STATUS_USED)
             ->first();
     }
+
+    private function judgeGroupUser($actor)
+    {
+        if($actor->isGuest() || $actor->isAdmin()){
+            return;
+        }
+        $db = $this->app->make('db');
+        $log = $this->app->make('log');
+        $group_user = app('cache')->get('judge_group_user_'.$actor->id);
+        if(empty($group_user)){
+            // 目前的业务中，保持着 user 与 group_user 一对一的关系，所以这里可以只取一个
+            $group_user = GroupUser::query()->where('user_id', $actor->id)->first();
+            app('cache')->put('judge_group_user_'.$actor->id, $group_user, self::CACHE_GROUP_USER_TIME);
+        }
+        if($group_user->expiration_time < Carbon::now()){
+            //判断用户当前是否为付费用户组，如果是付费用户组，还需要切换成普通用户组
+            $paid_group = $group_user->groups()->where('is_paid', Group::IS_PAID)->first();
+            if(empty($paid_group)){         //如果是普通用户组了，就不再进行切换身份操作了
+                return;
+            }
+            //用户当前用户组到期，需要切换用户组
+            $group_user_mqs = GroupUserMq::query()
+                            ->select('groups.id','group_user_mqs.remain_days')
+                            ->join('groups', 'group_user_mqs.group_id','=','groups.id')
+                            ->where('group_user_mqs.user_id', $actor->id)
+                            ->orderBy('groups.level', 'desc')
+                            ->first();
+
+            $db->beginTransaction();
+            //先删掉之前的 group_user
+            $res = GroupUser::query()->where(['user_id' => $actor->id, 'group_id' => $group_user->group_id])->delete();
+            if($res === false){
+                $db->rollBack();
+                $log->error('删除 group_user 出错', [$actor]);
+                return;
+            }
+            //修改对应的 group_paid_user 的 delete_type 为 1
+            $res = GroupPaidUser::query()
+                ->where('group_id', $group_user->group_id)
+                ->where('user_id', $group_user->user_id)
+                ->where('delete_type', 0)
+                ->update(['deleted_at' => Carbon::now(), 'delete_type' => GroupPaidUser::DELETE_TYPE_EXPIRE]);
+            if($res === false){
+                $db->rollBack();
+                $log->error('删除  group_paid_user 出错', [$actor]);
+                return;
+            }
+            //再新增新的 group_user ，默认普通用户组
+            $change_group_id = Group::query()->where('default', true)->value('id') ?? Group::MEMBER_ID;
+            $change_expired_at = $actor->expired_at;
+            if(!empty($group_user_mqs)){
+                $change_group_id = $group_user_mqs->id;
+                $change_expired_at = Carbon::now()->addDays($group_user_mqs->remain_days);
+                //删除对应的 group_user_mqs
+                $res = GroupUserMq::query()->where(['user_id' => $actor->id, 'group_id' => $group_user_mqs->id])->delete();
+                if($res === false){
+                    $db->rollBack();
+                    $log->error('删除 group_user_mqs 出错', [$actor]);
+                    return;
+                }
+            }
+
+            $res = $db->table('group_user')->insert([
+                        'group_id'  =>  $change_group_id,
+                        'user_id'   =>  $actor->id,
+                        'expiration_time'   =>  $change_expired_at
+                    ]);
+            if($res === false){
+                $db->rollBack();
+                $log->error('切换 group_user 成默认用户组出错', [$actor]);
+                return;
+            }
+            // 更新 group_user 之后需要刷新缓存
+            $group_user = GroupUser::query()->where('user_id', $actor->id)->first();
+            app('cache')->put('judge_group_user_'.$actor->id, $group_user, self::CACHE_GROUP_USER_TIME);
+            $db->commit();
+        }
+    }
 }