diff --git a/app/api/mobile/apis/courses.rb b/app/api/mobile/apis/courses.rb
index 6d68d549a..08c7adf10 100644
--- a/app/api/mobile/apis/courses.rb
+++ b/app/api/mobile/apis/courses.rb
@@ -80,6 +80,10 @@ module Mobile
             class_period: params[:class_period]
           }
           course = ::Course.find(params[:course_id])
+          # 如果没有传密码过来，那就把原来的密码给上，不然会不更新
+          if params[:password].nil? || params[:password].blank?
+            cs_params[:course][:password] = course[:password]
+          end
           cs.edit_course_authorize(current_user,course)
           course = cs.edit_course(cs_params, course,current_user)
           present :data, course, with: Mobile::Entities::Course