diff --git a/app/controllers/homework_commons_controller.rb b/app/controllers/homework_commons_controller.rb
index 9780b4eec..9b77f8dc7 100644
--- a/app/controllers/homework_commons_controller.rb
+++ b/app/controllers/homework_commons_controller.rb
@@ -109,7 +109,7 @@ class HomeworkCommonsController < ApplicationController
 
     logger.info("###########______@homework.publish_time_________#{@homework.publish_time}")
 
-    if @homework.publish_time.present? || (@homework.publish_time > Time.now)
+    if @homework.publish_time.blank? || (@homework.publish_time > Time.now)
       @student_works = []
       if (params[:format] == "xlsx") || (params[:format] == "zip")
         normal_status(-1,"作业未发布")