diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index 2287e1968..217c47866 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -363,8 +363,20 @@ class ProjectsController < ApplicationController
     # 该邮箱未注册过
     if !params[:mail].blank? && User.find_by_mail(params[:mail].to_s).nil?
       if !User.where("login =?", params[:mail]).first.nil?
-        # 用户名唯一，如果该邮箱被用户作为用户名使用则跳出
-        flash[:error] = l(:notice_email_login_used)
+        # 用户名唯一，用户修改邮箱，未修改用户名，用户名等同邮箱的情况，默认改用户已经注册
+        user = User.find_by_login(params[:mail].to_s)
+        if !user.member_of?(@project)
+          # 如果已经邀请过该用户，则不重复发送
+          if InviteList.where("project_id =? and mail =?", @project.id, params[:mail].to_s).first.nil?
+            email = params[:mail]
+            Mailer.request_member_to_project(email, @project, User.current).deliver
+            flash[:notice] = l(:notice_email_sent, :value => email)
+          else
+            flash[:error] = l(:notice_email_invited)
+          end
+        else
+          flash[:error] = l(:label_member_of_project, :value => email)
+        end
       else
         email = params[:mail]
         Mailer.send_invite_in_project(email, @project, User.current).deliver