diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 286935c17..6b686e0e7 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -53,7 +53,6 @@ class CoursesController < ApplicationController
       #                        c.tea_id=u.id and u.id=ue.user_id and ue.school_id=s.id")
 
       @courses = Course.where(is_delete: 0, is_hidden: 0)
-                     .includes(:course_modules, :course_members, teacher: [user_extension: :school])
                      .order("courses.id = 1309 desc, courses.created_at desc")
 
       # @courses = Course.where(is_delete: 0, is_hidden: 0).select("courses.id, courses.tea_id, courses.name, courses.exercises_count, courses.polls_count,
@@ -66,13 +65,11 @@ class CoursesController < ApplicationController
                        .order("courses.id = 1309 DESC, courses.#{order_str} DESC")
     elsif @order == "created_at"
       # REDO:Extension
-      @courses = Course.joins(teacher: :user_extension)
-                       .where(is_delete: 0, is_hidden: 0, is_end: 0)
+      @courses = Course.where(is_delete: 0, is_hidden: 0, is_end: 0)
                        .order("courses.id = 1309 DESC, courses.#{order_str} DESC")
     else
       # REDO:Extension
-      @courses = Course.joins(teacher: :user_extension)
-                       .where(is_delete: 0, is_hidden: 0)
+      @courses = Course.where(is_delete: 0, is_hidden: 0)
                        .order("courses.id = 1309 DESC, courses.#{order_str} DESC")
     end
 
@@ -89,7 +86,7 @@ class CoursesController < ApplicationController
         (course_members.role in(1,2,3) and CONCAT(users.lastname, users.firstname) like :keyword) or courses.name like :keyword
         or schools.name like :keyword
       }
-      @courses = @courses.joins(course_members: [user: [user_extension: :school]])
+      @courses = @courses.joins(:school, course_members: [user: :user_extension])
                      .where("#{sql}", keyword: "%#{params[:search]}%").distinct
     end
     @courses_count = @courses.size
@@ -98,7 +95,8 @@ class CoursesController < ApplicationController
     page  = params[:page]  || 1
     limit = params[:limit] || 16
 
-    @courses= @courses.page(page).per(limit)
+    @courses = @courses.page(page).per(limit)
+    @courses = @courses.preload(:school, :course_members, teacher: :user_extension)
   end
 
   def visits_plus_one
@@ -655,7 +653,8 @@ class CoursesController < ApplicationController
 
     page = params[:page] || 1
     limit = params[:limit] || 20
-    @students= Kaminari.paginate_array(@students).page(page).per(limit)
+    @students= @students.page(page).per(limit)
+    @students = @students.includes(:course_group, user: :user_extension)
   end
 
   # 获取当前课程所有分班
diff --git a/app/models/user.rb b/app/models/user.rb
index 7e04ff423..523df045d 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -318,7 +318,12 @@ class User < ApplicationRecord
     elsif business?
       Course::BUSINESS
     else
-      role = course.course_members.find_by(user_id: id, is_active: 1)&.role
+      role =
+        if course.course_members.loaded?
+          course.course_members.find{|member| member.user_id == id && member.is_active == 1}&.role
+        else
+          course.course_members.find_by(user_id: id, is_active: 1)&.role
+        end
       case role
       when nil                   then Course::NORMAL
       when 'CREATOR'             then Course::CREATOR
diff --git a/app/views/courses/index.json.jbuilder b/app/views/courses/index.json.jbuilder
index 5a128a0b7..2b6866517 100644
--- a/app/views/courses/index.json.jbuilder
+++ b/app/views/courses/index.json.jbuilder
@@ -1,18 +1,15 @@
-json.courses do
-  json.array! @courses do |course|
+json.courses @courses do |course|
     json.id course.id
     json.name course.name
     json.avatar_url url_to_avatar(course.teacher)
     json.creator course.teacher.real_name
-    json.school course.teacher.school_name
-    json.technical_title course.teacher.user_extension.technical_title
+    json.school course.school&.name
+    json.technical_title course.teacher.identity
     json.course_members_count course.course_members_count
     json.tasks_count get_tasks_count course
     json.visits course.visits
     json.is_public course.is_public
     json.is_accessible course.is_public == 1 || @user.course_identity(course) < Course::NORMAL
     json.is_end course.is_end
-    json.first_category_url module_url(course.course_modules.not_hidden.first, course)
-  end
 end
 json.courses_count @courses_count