diff --git a/src/SKIT.FlurlHttpClient.Wechat.Work/Extensions/WechatWorkClientEventExtensions.cs b/src/SKIT.FlurlHttpClient.Wechat.Work/Extensions/WechatWorkClientEventExtensions.cs
index a819394f..f048e65b 100644
--- a/src/SKIT.FlurlHttpClient.Wechat.Work/Extensions/WechatWorkClientEventExtensions.cs
+++ b/src/SKIT.FlurlHttpClient.Wechat.Work/Extensions/WechatWorkClientEventExtensions.cs
@@ -1,7 +1,5 @@
 using System;
 using System.IO;
-using System.Text;
-using System.Text.RegularExpressions;
 using System.Xml.Linq;
 using System.Xml.Serialization;
 
@@ -209,18 +207,7 @@ namespace SKIT.FlurlHttpClient.Wechat.Work
 
             try
             {
-                using var stream = new MemoryStream();
-                using var writer = new System.Xml.XmlTextWriter(stream, Encoding.UTF8);
-                writer.Formatting = System.Xml.Formatting.None;
-
-                XmlSerializer xmlSerializer = new XmlSerializer(typeof(TEvent), new XmlRootAttribute("xml"));
-                XmlSerializerNamespaces xmlNamespace = new XmlSerializerNamespaces();
-                xmlNamespace.Add(string.Empty, string.Empty);
-                xmlSerializer.Serialize(writer, callbackModel, xmlNamespace);
-                writer.Flush();
-                xml = Encoding.UTF8.GetString(stream.ToArray());
-                xml = Regex.Replace(xml, "\\s+<\\w+ (xsi|d2p1):nil=\"true\"[^>]*/>", string.Empty, RegexOptions.IgnoreCase);
-                xml = Regex.Replace(xml, "<\\?xml[^>]*\\?>", string.Empty, RegexOptions.IgnoreCase);
+                xml = Utilities.XmlUtility.Serialize(callbackModel);
             }
             catch (Exception ex)
             {
diff --git a/src/SKIT.FlurlHttpClient.Wechat.Work/Utilities/Internal/XmlUtility.cs b/src/SKIT.FlurlHttpClient.Wechat.Work/Utilities/Internal/XmlUtility.cs
new file mode 100644
index 00000000..6c63464b
--- /dev/null
+++ b/src/SKIT.FlurlHttpClient.Wechat.Work/Utilities/Internal/XmlUtility.cs
@@ -0,0 +1,44 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Xml;
+using System.Xml.Serialization;
+
+namespace SKIT.FlurlHttpClient.Wechat.Work.Utilities
+{
+    internal static class XmlUtility
+    {
+        public static string Serialize(Type type, object obj)
+        {
+            string xml;
+
+            var settings = new XmlWriterSettings();
+            settings.Encoding = Encoding.UTF8;
+            settings.Indent = false;
+            settings.OmitXmlDeclaration = true;
+            settings.WriteEndDocumentOnClose = false;
+            settings.NamespaceHandling = NamespaceHandling.OmitDuplicates;
+
+            using var stream = new MemoryStream();
+            using var writer = XmlWriter.Create(stream, settings);
+
+            XmlSerializer xmlSerializer = new XmlSerializer(type, new XmlRootAttribute("xml"));
+            XmlSerializerNamespaces xmlNamespace = new XmlSerializerNamespaces();
+            xmlNamespace.Add(string.Empty, string.Empty);
+            xmlSerializer.Serialize(writer, obj, xmlNamespace);
+            writer.Flush();
+            xml = Encoding.UTF8.GetString(stream.ToArray());
+            xml = Regex.Replace(xml, "\\s*<\\w+ (xsi|d2p1):nil=\"true\"[^>]*/>", string.Empty, RegexOptions.IgnoreCase);
+            xml = Regex.Replace(xml, "<\\?xml[^>]*\\?>", string.Empty, RegexOptions.IgnoreCase);
+
+            return xml;
+        }
+
+        public static string Serialize<T>(T obj)
+            where T : class
+        {
+            return Serialize(typeof(T), obj);
+        }
+    }
+}