diff --git a/app/helpers/activities_helper.rb b/app/helpers/activities_helper.rb
index cf8679da6..822613455 100644
--- a/app/helpers/activities_helper.rb
+++ b/app/helpers/activities_helper.rb
@@ -44,6 +44,9 @@ module ActivitiesHelper
   end
 
   def get_container_type(activity)
+    if activity.act.nil?
+      return ['Unknow',0]
+    end
     #问卷
     if activity.act_type == 'Poll'
       return ['Course',activity.act.polls_group_id]