diff --git a/Gemfile b/Gemfile
index 6d0c1bf30..a53f2bc66 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,6 +7,7 @@ unless RUBY_PLATFORM =~ /w32/
     gem "rmagick", "= 2.15.4" ## osx must be this version
   elsif RUBY_PLATFORM =~ /linux/
     gem "rmagick", "~> 2.13.1" ## centos yum install ImageMagick-devel
+    gem 'simple_xlsx_reader'
   end
   gem 'certified'
   gem 'net-ssh', '2.9.1'
@@ -14,7 +15,6 @@ unless RUBY_PLATFORM =~ /w32/
   gem 'nokogiri'
 end
 
-gem 'simple_xlsx_reader'
 gem 'wechat',path: 'lib/wechat'
 gem 'grack', path:'lib/grack'
 gem 'gitlab', path: 'lib/gitlab-cli'
diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 396f0c06b..bcd6e1422 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -32,7 +32,9 @@ class CoursesController < ApplicationController
 
   before_filter :require_login, :only => [:join, :unjoin]
   #before_filter :allow_join, :only => [:join]
-  require 'simple_xlsx_reader'
+  if RUBY_PLATFORM =~ /linux/
+    require 'simple_xlsx_reader'
+  end
 
   def sync_temp_excel
     # unless User.current.admin?
diff --git a/app/helpers/courses_helper.rb b/app/helpers/courses_helper.rb
index 2632a3f2c..d98497bed 100644
--- a/app/helpers/courses_helper.rb
+++ b/app/helpers/courses_helper.rb
@@ -412,7 +412,7 @@ module CoursesHelper
     members = []
     project.members.includes(:user).each do |m|
       #members << m  if m && m.user && m.user.allowed_to?(:as_teacher,project)
-      members << m  if m && m.user && m.user.has_teacher_role(project)
+      members << m if m && m.user && m.user.has_teacher_role(project)
     end
     members
   end
diff --git a/app/views/layouts/_course_base_info.html.erb b/app/views/layouts/_course_base_info.html.erb
index 174e8e3c1..54499d176 100644
--- a/app/views/layouts/_course_base_info.html.erb
+++ b/app/views/layouts/_course_base_info.html.erb
@@ -1,5 +1,6 @@
 <% is_teacher = User.current.logged? && (User.current.admin? || User.current.allowed_to?(:as_teacher,@course)) %>
-<% teacher_num = TeacherAndAssistantCount(@course) %>
+<% teacher_num = Member.find_by_sql("SELECT count(*) as teacher_count FROM `member_roles` mr,  `members` m where m.course_id=#{@course.id}
+                                    and m.id=mr.member_id and mr.role_id in ('3','7','9')").first.try(:teacher_count) %>
 <% student_num = studentCount(@course) %>
 <% course_file_num = visable_attachemnts_incourse(@course).count %>
 <p class="sy_cgrey mb10 mr20">