diff --git a/app/controllers/files_controller.rb b/app/controllers/files_controller.rb
index 03e6dad24..6a7f7b4b0 100644
--- a/app/controllers/files_controller.rb
+++ b/app/controllers/files_controller.rb
@@ -18,11 +18,23 @@ class FilesController < ApplicationController
     sort_type = params[:sort_type] || 'created_on' # created_on：时间排序， downloads：下载次数排序; quotes: 引用次数排序
     @course_second_category_id = params[:course_second_category_id] || 0 # 0: 为主目录， 其他为次目录id
     @user = current_user
-    @attachments = @course_second_category_id.to_i == 0 ? @course.attachments.includes(:course_second_category) : @course.attachments.by_course_second_category_id(@course_second_category_id)
+    get_category(@course, @course_second_category_id)
+
+    # 主目录显示所有资源，一级目录显示一级和所属二级目录的资源，二级目录只显示该目录下的资源
+    if @course_second_category_id.to_i == 0
+      @attachments = @course.attachments.includes(:course_second_category)
+    else
+      if @parent_category_id == 0
+        category_ids = [@category_id] + @category.children.pluck(:id)
+        @attachments = @course.attachments.where(course_second_category_id: category_ids)
+      else
+        @attachments = @course.attachments.by_course_second_category_id(@course_second_category_id)
+      end
+    end
+
     @attachments = @attachments.includes(author: [:user_extension, :course_members])
                        .ordered(sort: sort.to_i, sort_type: sort_type.strip)
 
-    get_category(@course, @course_second_category_id)
     @total_count = @attachments.size
     @unlink_count = @attachments.no_link.size
 
@@ -354,9 +366,10 @@ class FilesController < ApplicationController
       @category_id = category.try(:id)
       @category_name = category.try(:module_name)
     else
-      category = CourseSecondCategory.find category_id
+      @category = CourseSecondCategory.find category_id
       @category_id = category.try(:id)
       @category_name = category.try(:name)
+      @parent_category_id = category&.parent_id.to_i
     end
   end
 
diff --git a/app/views/files/index.json.jbuilder b/app/views/files/index.json.jbuilder
index e0c21e232..07430cd7b 100644
--- a/app/views/files/index.json.jbuilder
+++ b/app/views/files/index.json.jbuilder
@@ -7,6 +7,7 @@ json.data do
   json.unpublish_count @unpublish_count
   json.unlink_count @unlink_count
   json.course_is_public @course.is_public?
+  json.parent_category_id @parent_category_id
   json.files do
     json.array! @attachments do |attachment|
       json.is_history_file attachment.attachment_histories.count > 0 #是否有历史文件
@@ -16,7 +17,7 @@ json.data do
       end
       # json.partial! "files/course_groups", attachment_group_settings: attachment.attachment_group_settings
       json.category_id attachment.course_second_category_id
-      if @course_second_category_id.to_i == 0
+      unless @parent_category_id.present? && @parent_category_id != 0
         json.category_name attachment.course_second_category&.name
       end
     end