diff --git a/docs/en/client/java-sdk-user-guide.md b/docs/en/client/java-sdk-user-guide.md
index 45521eca3e3..6a6a814b83a 100644
--- a/docs/en/client/java-sdk-user-guide.md
+++ b/docs/en/client/java-sdk-user-guide.md
@@ -431,7 +431,7 @@ namespace: Use the specified value, if not specified, the default is "default"
 
 configMapName: apollo-configcache-{appId}
 
-key: {cluster} - {namespace}
+key:{cluster}___{namespace}
 
 value: The content is the JSON format string of the corresponding configuration information.
 
@@ -439,7 +439,9 @@ value: The content is the JSON format string of the corresponding configuration
 > 
 > cluster is the cluster used by the application, which is usually default if not configured locally 
 > 
-> namespace is the configuration namespace used by the application, which is generally application
+> namespace Indicates the configuration namespace used by the application. If '_' appears in the namespace, it will be escaped to '__' when the key is concatenated.
+
+> Since this feature is extended, so the client-java dependency is set to optional. You need to import the matching version
 
 > Since read and write operations on the ConfigMap are required, the pod where the client is located must have the corresponding permissions. The specific configuration method can be referred to below.
 
diff --git a/docs/zh/client/java-sdk-user-guide.md b/docs/zh/client/java-sdk-user-guide.md
index 220569e405f..f3c66349254 100644
--- a/docs/zh/client/java-sdk-user-guide.md
+++ b/docs/zh/client/java-sdk-user-guide.md
@@ -416,14 +416,16 @@ namespace：使用指定的值，若未指定默认为"default"
 
 configMapName: apollo-configcache-{appId}
 
-key:{cluster}-{namespace}
+key:{cluster}___{namespace}
 
 value:内容为对应的配置信息的json格式字符串
 
 
 > appId是应用自己的appId，如100004458    
 > cluster是应用使用的集群，一般在本地模式下没有做过配置的话，是default  
-> namespace就是应用使用的配置namespace，一般是application
+> namespace就是应用使用的配置namespace。 如果namespace中出现‘_’ , 将会在拼接key时被转义为‘__’
+
+> 由于此功能为拓展功能，所以对于client-java的依赖设为了optional。需用户自行导入匹配的版本
 
 > 由于需要对configmap进行读写操作，所以客户端所在pod必须有相应读写权限，具体配置方法可参考下文