width: '600px'

public/react/src/modules/courses/members/teacherList.js

@@ -636,7 +636,7 @@ class studentsList extends Component{
             </React.Fragment>
           }
           secondRowLeft={
-            isAdminOrTeacher ? <div className="fl mt6 task_menu_ul ">
+            isAdminOrTeacher ? <div className="fl mt6 task_menu_ul " style={{ width: '600px' }}>
                 <Menu mode="horizontal" defaultSelectedKeys="1" onClick={this.selectedStatus}>
                   <Menu.Item key="1">已审批({total_count})</Menu.Item>
                   <Menu.Item key="2">待审批({apply_size})</Menu.Item>