diff --git a/registry/nacos/registry.go b/registry/nacos/registry.go
index 3600a8e1fa..670a2c5e88 100644
--- a/registry/nacos/registry.go
+++ b/registry/nacos/registry.go
@@ -75,8 +75,8 @@ func getServiceName(url *common.URL) string {
 
 func appendParam(target *bytes.Buffer, url *common.URL, key string) {
 	value := url.GetParam(key, "")
+	target.Write([]byte(constant.NACOS_SERVICE_NAME_SEPARATOR))
 	if strings.TrimSpace(value) != "" {
-		target.Write([]byte(constant.NACOS_SERVICE_NAME_SEPARATOR))
 		target.Write([]byte(value))
 	}
 }