diff --git a/documents/help/ecs/configure-IPv6-address-for-ecs.yml b/documents/help/ecs/configure-IPv6-address-for-ecs.yml
index 156a8015..5b9380ec 100644
--- a/documents/help/ecs/configure-IPv6-address-for-ecs.yml
+++ b/documents/help/ecs/configure-IPv6-address-for-ecs.yml
@@ -115,6 +115,14 @@ Parameters:
   CommonName:
     Type: String
     Default: config-ipv6
+  Ipv6CidrBlockNumber:
+    Type: Number
+    AssociationProperty: AutoCompleteInput
+    AssociationPropertyMetadata:
+      Length: 2
+      CharacterClasses:
+        - Class: number
+          min: 1
 Conditions:
   CreateInstance:
     Fn::Equals:
@@ -524,6 +532,8 @@ Resources:
           Fn::GetAtt:
             - DsVsw
             - Ipv6CidrBlock
+        Ipv6CidrBlockNumber:
+          Ref: Ipv6CidrBlockNumber
       TemplateBody:
         ROSTemplateFormatVersion: '2015-09-01'
         Parameters:
@@ -544,6 +554,8 @@ Resources:
           Ipv6InternetBandwidthId:
             Type: String
             Default: null
+          Ipv6CidrBlockNumber:
+            Type: Number
         Conditions:
           EnableIpv6ForVpc:
             Fn::Equals:
@@ -599,7 +611,8 @@ Resources:
               API: ModifyVSwitchAttribute
               Method: POST
               Parameters:
-                Ipv6CidrBlock: 252
+                Ipv6CidrBlock:
+                  Ref: Ipv6CidrBlockNumber
                 VSwitchId:
                   Ref: VswId
                 EnableIPv6: true
@@ -663,5 +676,6 @@ Metadata:
           - EcsInstanceId
     Hidden:
       - CommonName
+      - Ipv6CidrBlockNumber
     TemplateTags:
       - acs:document-help:ecs:配置ECS实例的IPv6地址