diff --git a/Gemfile b/Gemfile
index 65a0dbfb6..402bcd0c7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -145,3 +145,6 @@ gem 'doorkeeper'
 gem 'doorkeeper-jwt'
 
 gem 'gitea-client', '~> 1.4.2'
+
+# 阿里云oss
+gem 'aliyun-sdk', '~> 0.8.0'
diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index 0cdba3847..e928e378c 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -14,6 +14,8 @@ class AttachmentsController < ApplicationController
     # 2. 如果没有cdn，send_file
     if @file.cloud_url.present?
       update_downloads(@file)
+      
+      cloud_url = @file.get_cloud_url
       redirect_to @file.cloud_url and return
     end
 
@@ -258,4 +260,25 @@ class AttachmentsController < ApplicationController
     end
   end
 
+  def get_cloud_url(disposition="attachment")
+    if (self.container_type == "Shixun" && [11, 12, 13].include?(self.attachtype)) ||
+      ((["VirtualClassroomGoodLesson", "VirtualClassroomDiscussion", "Course"].include?(self.container_type)) && self.attachtype == 11) ||
+      (self.container_type == "VirtualClassroomGoodLesson"  && self.attachtype == 30) ||
+      (self.container_type == "VirtualClassroomDiscussion"  && self.attachtype == 31)
+      cloud_url = self.oss_absolute_url
+    elsif self.digest.start_with?(SLUG_PREFIX)
+      bucket = %w[SmartPlan].include?(self.container_type) ? OSS.client.get_bucket(OSS.bucket_big_files) : OSS.client.get_bucket(OSS.attachments_oss_bucket)
+      cloud_url = bucket.object_url(self.cloud_url, true, 10 * 3600 * 24, {"response-content-disposition": "attachment;\"filename=#{URI.encode(self.filename.strip)}\";attachment_id=#{self.id}"})
+    elsif ["Stage", "Course"].include?(self.container_type) && OSS.client.get_bucket(OSS.bucket_big_files).object_exists?(self.cloud_url)
+      cloud_url = ApplicationController.helpers.cdn_a_auth_url(self)
+    elsif self.cloud_url.include?("http")
+      cloud_url = self.cloud_url
+    else
+      bucket = OSS.client.get_bucket(OSS.attachments_oss_bucket)
+      cloud_url = bucket.object_url(self.cloud_url, true, 10 * 3600 * 24, {"response-content-disposition": "attachment;\"filename=#{URI.encode(self.filename.strip)}\";attachment_id=#{self.id}"})
+    end
+    cloud_url
+  end
+
+
 end
diff --git a/config/initializers/aliyun_oss_init.rb b/config/initializers/aliyun_oss_init.rb
new file mode 100644
index 000000000..f20b6407d
--- /dev/null
+++ b/config/initializers/aliyun_oss_init.rb
@@ -0,0 +1,84 @@
+require 'aliyun/sts'
+require 'aliyun/oss'
+module OSS
+  def self.client
+    unless @client
+      #Aliyun::OSS::Logging.set_log_file("#{Rails.root}/log/oss_sdk.log")
+      @client = Aliyun::OSS::Client.new(
+          endpoint: aliyun_vod_config['endpoint'],
+          cname: aliyun_vod_config['cname'],
+          access_key_id: aliyun_vod_config['access_key_id'],
+          access_key_secret: aliyun_vod_config['access_key_secret']
+      )
+    end
+
+    @client
+  end
+
+  def self.public_bucket_client
+    @public_bucket_client = Aliyun::OSS::Client.new(
+      endpoint: aliyun_vod_config['public_bucket_endpoint'],
+      cname: aliyun_vod_config['cname'],
+      access_key_id: aliyun_vod_config['access_key_id'],
+      access_key_secret: aliyun_vod_config['access_key_secret']
+    )
+  end
+
+  def self.end_point
+    aliyun_vod_config['endpoint']
+  end
+
+  def self.access_key_id
+    aliyun_vod_config['access_key_id']
+  end
+
+  def self.access_key_secret
+    aliyun_vod_config['access_key_secret']
+  end
+
+  def self.bucket
+    aliyun_vod_config['bucket']
+  end
+
+  # 公共库
+  def self.public_bucket
+    aliyun_vod_config['public_bucket']
+  end
+
+  # attachments 附件存储库
+  def self.attachments_oss_bucket
+    aliyun_vod_config['attachments_oss']
+  end
+
+  #实训大数据集
+  def self.bucket_big_files
+    aliyun_vod_config['bucket_big_files']
+  end
+
+  def self.region
+    aliyun_vod_config['region']
+  end
+
+  def self.aliyun_vod_config
+    Rails.application.config_for(:configuration)['aliyun_oss']
+  end
+end
+
+module STS
+  def self.client
+    unless @sts_client
+      config = Rails.application.config_for(:configuration)
+      aliyun_vod_config = config['aliyun_oss']
+      @sts_client = Aliyun::STS::Client.new(
+          access_key_id: aliyun_vod_config['access_key_id'],
+          access_key_secret: aliyun_vod_config['access_key_secret'])
+
+    end
+
+    @sts_client
+  end
+
+  def self.role_arn
+    "acs:ram::1829848226361863:role/oss-anticheat".freeze
+  end
+end