diff --git a/app/controllers/homework_common_controller.rb b/app/controllers/homework_common_controller.rb
index 0d6a1a0e7..8da82afd3 100644
--- a/app/controllers/homework_common_controller.rb
+++ b/app/controllers/homework_common_controller.rb
@@ -11,6 +11,7 @@ class HomeworkCommonController < ApplicationController
   before_filter :member_of_course, :only => [:index]
 
   def index
+    update_homework_time(@course.homework_commons)
     @new_homework = HomeworkCommon.new
     @new_homework.homework_detail_manual = HomeworkDetailManual.new
     @new_homework.course = @course
@@ -385,4 +386,42 @@ class HomeworkCommonController < ApplicationController
     student_works += student_works
     student_works[index + 1 .. index + n]
   end
+
+  def update_homework_time homeworks
+    unless homeworks.nil?
+      homeworks.each do |h|
+        if h.homework_type == 3
+          student_works = h.student_works.where("project_id != 0")
+          time = h.updated_at
+          unless student_works.nil?
+            student_works.each do |s|
+              project = Project.find s.project_id
+              unless project.nil? && project.gpid.nil?
+                begin
+                  # gitlab端获取默认分支
+                  g = Gitlab.client
+                  default_branch = g.project(project.gpid).default_branch
+                  changesets = g.commits(project.gpid, :ref_name => default_branch)
+                  changesets_latest_coimmit = changesets[0]
+                  unless changesets[0].blank?
+                    if time < changesets_latest_coimmit.created_at
+                      time = changesets_latest_coimmit.created_at
+                    end
+                  end
+                rescue
+                  logger.error("############## ==> update homework project time")
+                end
+              end
+            end
+          end
+          puts h.updated_at
+          puts time
+          s_time = time
+          if format_time(time) > format_time(h.updated_at)
+            h.update_attribute(:updated_at, s_time)
+          end
+        end
+      end
+    end
+  end
 end
diff --git a/lib/tasks/homework_update.rake b/lib/tasks/homework_update.rake
new file mode 100644
index 000000000..b2246bfd5
--- /dev/null
+++ b/lib/tasks/homework_update.rake
@@ -0,0 +1,7 @@
+namespace :homework_update do
+  desc "update homework updated_at"
+  task :update_homework => :environment do
+    stu_pro = StudentWork.where("project_id != 0")
+
+  end
+end
\ No newline at end of file