diff --git a/messages/zh-CN/app.php b/messages/zh-CN/app.php
index b34854686..7798b2727 100644
--- a/messages/zh-CN/app.php
+++ b/messages/zh-CN/app.php
@@ -77,6 +77,7 @@
     'Release news' => '发布新闻',
     'Male' => '男',
     'Nickname' => '昵称',
+    'New Nickname' => '新昵称',
     'Prefix' => '前缀',
     'Number' => '数量',
     'Names' => '名称',
@@ -89,6 +90,7 @@
     'Verify Password' => '确认密码',
     'Female' => '女',
     'Major' => '专业',
+    'class' => '班级',
     'Contest' => '比赛',
     'Title' => '标题',
     'Type' => '类型',
diff --git a/migrations/m180401_030422_import_initial_table.php b/migrations/m180401_030422_import_initial_table.php
index a762740ae..3a764fc68 100644
--- a/migrations/m180401_030422_import_initial_table.php
+++ b/migrations/m180401_030422_import_initial_table.php
@@ -67,7 +67,8 @@ public function up()
             'description' => $this->string(),
             'school' => $this->string(),
             'student_number' => $this->string(64),
-            'major' => $this->string(64)
+            'major' => $this->string(64),
+            'class' => $this->string(64)
         ], $this->tableOptions);
 
         $this->execute('ALTER TABLE {{%user_profile}} ADD PRIMARY KEY(`user_id`);');
diff --git a/migrations/m190309_123832_setting.php b/migrations/m190309_123832_setting.php
index e31b86439..d3deae436 100644
--- a/migrations/m190309_123832_setting.php
+++ b/migrations/m190309_123832_setting.php
@@ -18,6 +18,8 @@ public function safeUp()
         $this->insert('{{%setting}}', ['key' => 'scoreboardFrozenTime', 'value' => '7200']);
         $this->insert('{{%setting}}', ['key' => 'isShareCode', 'value' => '1']);
         $this->insert('{{%setting}}', ['key' => 'oiMode', 'value' => '0']);
+        $this->insert('{{%setting}}', ['key' => 'SigninMode', 'value' => '1']);
+        $this->insert('{{%setting}}', ['key' => 'GroupMode', 'value' => '1']);
     }
 
     /**
@@ -30,6 +32,7 @@ public function safeDown()
         $this->delete('{{%setting}}', ['key' => 'scoreboardFrozenTime']);
         $this->delete('{{%setting}}', ['key' => 'isShareCode']);
         $this->delete('{{%setting}}', ['key' => 'oiMode']);
+        $this->delete('{{%setting}}', ['key' => 'SigninMode']);
         $this->dropColumn('{{%setting}}', 'id');
     }
 
diff --git a/models/User.php b/models/User.php
index c17c4c954..b59acd6e5 100644
--- a/models/User.php
+++ b/models/User.php
@@ -50,6 +50,7 @@ class User extends ActiveRecord implements IdentityInterface
     public $newPassword;
     public $verifyPassword;
 
+    public $newNickname;
     /**
      * 是否已经验证邮箱
      */
@@ -97,7 +98,9 @@ public function rules()
             [['oldPassword'], 'validateOldPassword'],
             [['verifyPassword'], 'compare', 'compareAttribute' => 'newPassword'],
             [['oldPassword', 'verifyPassword', 'newPassword'], 'required'],
-            ['newPassword', 'string', 'min' => 6, 'max' => 16]
+            ['newPassword', 'string', 'min' => 6, 'max' => 16],
+
+            [['newNickname'], 'string', 'max' => 16]
         ];
     }
 
@@ -120,6 +123,7 @@ public function attributeLabels()
             'id' => Yii::t('app', 'ID'),
             'username' => Yii::t('app', 'Username'),
             'nickname' => Yii::t('app', 'Nickname'),
+            'newNickname' => Yii::t('app', 'New Nickname'),
             'password' => Yii::t('app', 'Password'),
             'oldPassword' => Yii::t('app', 'Old Password'),
             'newPassword' => Yii::t('app', 'New Password'),
diff --git a/models/UserProfile.php b/models/UserProfile.php
index 034f63830..56c2e194e 100644
--- a/models/UserProfile.php
+++ b/models/UserProfile.php
@@ -40,6 +40,7 @@ public function rules()
             [['address', 'description', 'major'], 'string'],
             [['signature', 'school'], 'string', 'max' => 128],
             [['major'], 'string', 'max' => 64],
+            [['class'], 'string', 'max' => 64],
             [['user_id'], 'unique'],
         ];
     }
@@ -59,7 +60,8 @@ public function attributeLabels()
             'description' => Yii::t('app', 'Description'),
             'school' => Yii::t('app', 'School'),
             'student_number' => Yii::t('app', 'Student Number'),
-            'major' => Yii::t('app', 'Major')
+            'major' => Yii::t('app', 'Major'),
+            'class' => Yii::t('app', 'class')
         ];
     }
 }
diff --git a/modules/admin/controllers/UserController.php b/modules/admin/controllers/UserController.php
index a5a6909f6..50f77639f 100644
--- a/modules/admin/controllers/UserController.php
+++ b/modules/admin/controllers/UserController.php
@@ -122,6 +122,13 @@ public function actionUpdate($id)
         $model = $this->findModel($id);
 
         if (Yii::$app->request->isPost) {
+            $newNickname = Yii::$app->request->post('User')['newNickname'];
+            if (!empty($newNickname)) {
+                Yii::$app->db->createCommand()->update('{{%user}}', 
+                    ['username' => $newNickname, 'nickname' => $newNickname], 
+                    ['id' => $model->id]
+                )->execute();
+            }
             $newPassword = Yii::$app->request->post('User')['newPassword'];
             $role = Yii::$app->request->post('User')['role'];
             if (!empty($newPassword)) {
diff --git a/modules/admin/views/problem/index.php b/modules/admin/views/problem/index.php
index db471dcef..b3a79f7ac 100644
--- a/modules/admin/views/problem/index.php
+++ b/modules/admin/views/problem/index.php
@@ -58,6 +58,13 @@
                 },
                 'format' => 'raw'
             ],
+            [
+                'attribute' => 'tags',
+                'value' => function ($model, $key, $index, $column) {
+                    return Html::a(Html::encode($model->tags), ['problem/view', 'id' => $key]);
+                },
+                'format' => 'raw'
+            ],
             [
                 'attribute' => 'status',
                 'value' => function ($model, $key, $index, $column) {
diff --git a/modules/admin/views/setting/index.php b/modules/admin/views/setting/index.php
index f52e8ae14..ad8bb2603 100644
--- a/modules/admin/views/setting/index.php
+++ b/modules/admin/views/setting/index.php
@@ -19,7 +19,20 @@
         <?= Html::label(Yii::t('app', 'OJ名称'), 'ojName') ?>
         <?= Html::textInput('ojName', $settings['ojName'], ['class' => 'form-control']) ?>
     </div>
-
+    <div class="form-group">
+        <?= Html::label('注册功能', 'SigninMode') ?>
+        <?= Html::radioList('SigninMode', $settings['SigninMode'], [
+            1 => '启用',
+            0 => '禁用'
+        ]) ?>
+    </div>
+    <div class="form-group">
+        <?= Html::label('小组功能', 'GroupMode') ?>
+        <?= Html::radioList('GroupMode', $settings['GroupMode'], [
+            1 => '启用',
+            0 => '禁用'
+        ]) ?>
+    </div>
     <div class="form-group">
         <?= Html::label(Yii::t('app', 'OI 模式'), 'oiMode') ?>
         <?= Html::radioList('oiMode', $settings['oiMode'], [
diff --git a/modules/admin/views/user/_form.php b/modules/admin/views/user/_form.php
index 6f389ab89..c467cad4c 100644
--- a/modules/admin/views/user/_form.php
+++ b/modules/admin/views/user/_form.php
@@ -12,6 +12,8 @@
 
     <?php $form = ActiveForm::begin(); ?>
 
+    <?= $form->field($model, 'newNickname')->textInput() ?>
+
     <?= $form->field($model, 'newPassword')->textInput() ?>
 
     <?= $form->field($model, 'role')->radioList([
diff --git a/modules/admin/views/user/index.php b/modules/admin/views/user/index.php
index f35aaf560..1869f4b4c 100644
--- a/modules/admin/views/user/index.php
+++ b/modules/admin/views/user/index.php
@@ -74,6 +74,13 @@
                 },
                 'format' => 'raw'
             ],
+            [
+                'attribute' => Yii::t('app', 'class'),
+                'value' => function ($model, $widget) {
+                    return Html::encode($model->profile->class);
+                },
+                'format' => 'raw'
+            ],
             // 'status',
             // 'created_at',
             // 'updated_at',
diff --git a/modules/admin/views/user/update.php b/modules/admin/views/user/update.php
index 7fbcacf0d..9f1c03d85 100644
--- a/modules/admin/views/user/update.php
+++ b/modules/admin/views/user/update.php
@@ -9,14 +9,14 @@
     'username' => $model->username,
     'nickname' => $model->nickname
 ]);
-$this->params['breadcrumbs'][] = ['label' => Yii::t('app', 'Users'), 'url' => ['index']];
+$this->params['breadcrumbs'][] = ['label' => Yii::t('app', 'User'), 'url' => ['index']];
 $this->params['breadcrumbs'][] = ['label' => $model->id, 'url' => ['view', 'id' => $model->id]];
 $this->params['breadcrumbs'][] = Yii::t('app', 'Update');
 ?>
 <div class="user-update">
 
     <h1><?= Html::encode($this->title) ?></h1>
-
+    
     <?= $this->render('_form', [
         'model' => $model,
     ]) ?>
diff --git a/modules/admin/views/user/view.php b/modules/admin/views/user/view.php
index 0f59cc81f..e2e23ca6b 100644
--- a/modules/admin/views/user/view.php
+++ b/modules/admin/views/user/view.php
@@ -32,6 +32,13 @@
             'username',
             'created_at',
             'updated_at',
+            [
+                'attribute' => Yii::t('app', 'class'),
+                'value' => function ($model, $widget) {
+                    return Html::encode($model->profile->class);
+                },
+                'format' => 'raw'
+            ],
         ],
     ]) ?>
 
diff --git a/views/layouts/main.php b/views/layouts/main.php
index 5986b5f95..74de4e2fe 100644
--- a/views/layouts/main.php
+++ b/views/layouts/main.php
@@ -63,10 +63,6 @@
             'url' => ['/rating/problem'],
             'active' => Yii::$app->controller->id == 'rating'
         ],
-        [
-            'label' => '<span class="glyphicon glyphicon-user"></span> ' . Yii::t('app', 'Group'),
-            'url' => Yii::$app->user->isGuest ? ['/group/index'] : ['/group/my-group']
-        ],
         ['label' => '<span class="glyphicon glyphicon-knight"></span> ' . Yii::t('app', 'Contests'), 'url' => ['/contest/index']],
         [
             'label' => '<span class="glyphicon glyphicon-info-sign"></span> '. Yii::t('app', 'Wiki'),
@@ -74,8 +70,19 @@
             'active' => Yii::$app->controller->id == 'wiki'
         ],
     ];
+    if (!(Yii::$app->user->isGuest) && Yii::$app->user->identity->isAdmin()) {
+        $menuItems[] = ['label' => '<span class="glyphicon glyphicon-user"></span> ' . Yii::t('app', 'Group'),
+        'url' => Yii::$app->user->isGuest ? ['/group/index'] : ['/group/my-group']];
+    } else {
+        if (Yii::$app->setting->get('GroupMode') == "1") {
+            $menuItems[] = ['label' => '<span class="glyphicon glyphicon-user"></span> ' . Yii::t('app', 'Group'),
+                'url' => Yii::$app->user->isGuest ? ['/group/index'] : ['/group/my-group']];
+        }
+    }
     if (Yii::$app->user->isGuest) {
-        $menuItems[] = ['label' => '<span class="glyphicon glyphicon-new-window"></span> ' . Yii::t('app', 'Signup'), 'url' => ['/site/signup']];
+        if (Yii::$app->setting->get('SigninMode') == "1"){
+            $menuItems[] = ['label' => '<span class="glyphicon glyphicon-new-window"></span> ' . Yii::t('app', 'Signup'), 'url' => ['/site/signup']];
+        }
         $menuItems[] = ['label' => '<span class="glyphicon glyphicon-log-in"></span> ' . Yii::t('app', 'Login'), 'url' => ['/site/login']];
     } else {
         if (Yii::$app->user->identity->isAdmin()) {
diff --git a/views/user/_profile.php b/views/user/_profile.php
index d49f409a8..02bcd9a7a 100644
--- a/views/user/_profile.php
+++ b/views/user/_profile.php
@@ -11,15 +11,17 @@
 
 <?php $form = ActiveForm::begin(); ?>
 
-<?= $form->field($model, 'nickname')->textInput() ?>
+<?= $form->field($model, 'nickname')->textInput(['readonly' => true]) ?>
 
 <?= $form->field($profile, 'qq_number')->textInput() ?>
 
 <?= $form->field($profile, 'student_number')->textInput() ?>
 
-<?= $form->field($profile, 'gender')->radioList([Yii::t('app', 'Male'), Yii::t('app', 'Female')]) ?>
-
 <?= $form->field($profile, 'major')->textInput() ?>
+    
+<?= $form->field($profile, 'class')->textInput() ?>
+
+<?= $form->field($profile, 'gender')->radioList([Yii::t('app', 'Male'), Yii::t('app', 'Female')]) ?>
 
 <div class="form-group">
     <?= Html::submitButton(Yii::t('app', 'Save'), ['class' => 'btn btn-success']) ?>
diff --git a/views/user/view.php b/views/user/view.php
index 668813161..4499ff4b5 100644
--- a/views/user/view.php
+++ b/views/user/view.php
@@ -138,6 +138,13 @@ function showTooltip(x, y, contents) {
                             },
                             'format' => 'raw'
                         ],
+                        [
+                            'attribute' => Yii::t('app', 'class'),
+                            'value' => function ($model, $widget) {
+                                return Html::encode($model->profile->class);
+                            },
+                            'format' => 'raw'
+                        ],
                         [
                             'attribute' => Yii::t('app', 'Student Number'),
                             'value' => function ($model, $widget) {