diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index c46f9323a..7ff94c16a 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -1163,8 +1163,8 @@ class CoursesController < ApplicationController
     course_id = course.id
     course_name = course.name
     course_list_name = course.course_list.present? ? course.course_list.name : "--"
-    course_assistants = course.course_members.course_user_role(%i[PROFESSOR ASSISTANT_PROFESSOR])
-    course_assistants_count = course_assistants&.count
+    course_assistants = course.teachers
+    course_assistants_count = course_assistants&.size
     course_assistants_name = course_assistants_count > 0 ? course_assistants.map{|m| m.user.real_name}.join('、') : "--"
     course_teacher_member = course.course_members.course_user_role(%i[CREATOR])
     course_teacher = course_teacher_member.present? ? course_teacher_member.first.user.real_name : "--"
diff --git a/app/helpers/export_helper.rb b/app/helpers/export_helper.rb
index 76f51e498..b08cbb549 100644
--- a/app/helpers/export_helper.rb
+++ b/app/helpers/export_helper.rb
@@ -41,9 +41,9 @@ module ExportHelper
         w_user = w.user
         w_1 = (index + 1)
         if w_user.present?
-          w_2 = w_user&.login
-          w_3 = w_user&.real_name
-          w_3_1 = w_user&.mail
+          w_2 = w_user&.login.present? ? w_user&.login : "--"
+          w_3 = w_user&.real_name.present? ? w_user&.real_name : "--"
+          w_3_1 = w_user&.mail.present? ? w_user.mail : "--"
           w_4 = w_user.student_id.present? ? w_user.student_id : "--"
         else
           w_2 = "--"
@@ -129,9 +129,9 @@ module ExportHelper
         myshixun = w.try(:myshixun)
         w_user = w.user
         w_1 = (index + 1)
-        w_2 = w_user.login
-        w_3 = w_user.real_name
-        w_3_1 = w_user.mail
+        w_2 = w_user&.login.present? ? w_user&.login : "--"
+        w_3 = w_user&.real_name.present? ? w_user&.real_name : "--"
+        w_3_1 = w_user&.mail.present? ? w_user.mail : "--"
         w_4 = w_user.student_id.present? ? w_user.student_id : "--"
         course_name = course.students.find_by(user_id: w.user_id).try(:course_group_name)
         w_5 = course_name.present? ? course_name : "--"
@@ -214,9 +214,9 @@ module ExportHelper
     items.includes(user: :user_extension).each_with_index do |work,index|
       w_1 = (index+1)
       w_user = work.user
-      w_2 = w_user.login
-      w_3 = w_user.real_name
-      w_3_1 = w_user.mail
+      w_2 = w_user&.login.present? ? w_user&.login : "--"
+      w_3 = w_user&.real_name.present? ? w_user&.real_name : "--"
+      w_3_1 = w_user&.mail.present? ? w_user.mail : "--"
       w_4 = w_user.student_id.present? ? w_user.student_id : "--"
       w_5 = work.class_grouping_name
       if task_type_boolean   #是否分组
@@ -305,8 +305,11 @@ module ExportHelper
       user_start_time = e_user.start_at.present? ? e_user.start_at.strftime('%Y-%m-%d %H:%M') : "--"
       user_end_time = e_user.end_at.present? ? e_user.end_at.strftime('%Y-%m-%d %H:%M') : "--"
       user_student_id = user_info.student_id.present? ? user_info.student_id : "--"
+      user_login = user_info&.login.present? ? user_info.login : "--"
+      user_real_name = user_info.real_name.present? ? user_info.real_name : "--"
+      user_mail = user_info&.mail.present? ? user_info.mail : "--"
 
-      user_option = [index+1,user_info.login,user_info.real_name, user_info.mail || '--',
+      user_option = [index+1,user_login,user_real_name, user_mail,
                      user_student_id,user_course,user_commit_stu]
       if ques_type_boolean
         other_user_option = [user_obj_score,user_suj_score,user_score,user_start_time,user_end_time]
@@ -335,11 +338,11 @@ module ExportHelper
           topic = nil
         end
         w_1 = (index+1)
-        w_2 = user.login
-        w_3 = user.real_name
-        w_3_1 = user.mail
-        w_4 = user.student_id
-        w_5 = student.course_group_name
+        w_2 = user&.login.present? ? user&.login : "--"
+        w_3 = user&.real_name.present? ? user&.real_name : "--"
+        w_3_1 = user&.mail.present? ? user.mail : "--"
+        w_4 = user.student_id.present? ? user.student_id : "--"
+        w_5 = student&.course_group_name.present? ? student.course_group_name : "--"
         w_6 = topic.present? ? topic.name : "--"
         w_7 = topic.present? ? topic.teacher.full_name : "--"
         w_8 = topic.present? ? topic.teacher.identity : "--"