更改：文件返回type

app/controllers/api/pm/issues_controller.rb

@@ -153,7 +153,7 @@ class Api::Pm::IssuesController < Api::Pm::BaseController
       p.serialize('public/导出工作项.xlsx')
     end
 
-    send_file('public/导出工作项.xlsx')
+    send_file('public/导出工作项.xlsx', :type => 'application/octet-stream;charset=utf-8')
   end
 
   def import