diff --git a/app/controllers/student_works_controller.rb b/app/controllers/student_works_controller.rb
index 680c067f7..dfdce7bd2 100644
--- a/app/controllers/student_works_controller.rb
+++ b/app/controllers/student_works_controller.rb
@@ -529,7 +529,7 @@ class StudentWorksController < ApplicationController
     @echart_data = student_efficiency(@homework, @work)
     @myself_eff = @echart_data[:efficiency_list].find { |item| item.last == @user.id }
     @myself_consume = @echart_data[:consume_list].find { |item| item.last == @user.id }
-    filename_ = "#{@use&.student_id}_#{@use&.real_name}_#{@shixun&.name}_#{Time.now.strftime('%Y%m%d_%H%M%S')}"
+    filename_ = "#{@use&.student_id}_#{@use&.real_name}_#{@shixun&.name}_#{Time.now.strftime('%Y%m%d_%H%M%S')}.pdf"
     filename = filename_.strip.tr("+/", "-_")
     stylesheets = %w(shixun_work/shixun_work.css shared/codemirror.css)
     if params[:export].present? && params[:export]