diff --git a/app/services/duplicate_course_service.rb b/app/services/duplicate_course_service.rb
index 9d61984db..8d6ce4f72 100644
--- a/app/services/duplicate_course_service.rb
+++ b/app/services/duplicate_course_service.rb
@@ -38,7 +38,12 @@ class DuplicateCourseService < ApplicationService
   def copy_course_modules!
     origin_course.course_modules.each do |course_module|
       attrs = course_module.as_json(only: %i[module_type position hidden module_name])
-      CourseModule.create!(attrs.merge(course_id: course.id))
+      new_course_module = CourseModule.create!(attrs.merge(course_id: course.id))
+      # 复制子目录
+      course_module.course_second_categories.each do |second_category|
+        category_attr =  second_category.as_json(only: %i[category_type name position])
+        CourseSecondCategory.create!(category_attr.merge(course_id: course.id, course_module_id: new_course_module.id))
+      end
     end
   end