diff --git a/app/helpers/courses_helper.rb b/app/helpers/courses_helper.rb
index 8c88f02d0..a56eb27a6 100644
--- a/app/helpers/courses_helper.rb
+++ b/app/helpers/courses_helper.rb
@@ -246,15 +246,17 @@ module CoursesHelper
 
   def left_group_info course
     group_info = []
-    course.course_groups.each do |course_group|
-      group_info << {category_id: course_group.id, category_name: course_group.name, position: course_group.position,
-                     category_count: course_group.course_members_count, category_type: false,
-                     second_category_url: "/courses/#{@course.id}/course_groups/#{course_group.id}"}
+    if course.course_groups_count > 0
+      course.course_groups.each do |course_group|
+        group_info << {category_id: course_group.id, category_name: course_group.name, position: course_group.position,
+                       category_count: course_group.course_members_count, category_type: false,
+                       second_category_url: "/courses/#{@course.id}/course_groups/#{course_group.id}"}
+      end
+      none_group_count = course.students.where(course_group_id: 0).size
+      group_info << {category_id: 0, category_name: "未分班", position: course.course_groups.pluck(:position).max.to_i + 1,
+                     category_count: none_group_count, category_type: false,
+                     second_category_url: "/courses/#{@course.id}/course_groups/0"}
     end
-    none_group_count = course.students.where(course_group_id: 0).size
-    group_info << {category_id: 0, category_name: "未分班", position: course.course_groups.pluck(:position).max.to_i + 1,
-                   category_count: none_group_count, category_type: false,
-                   second_category_url: "/courses/#{@course.id}/course_groups/0"}
   end
 
 end