diff --git a/Common/Common/Http/LCHttpClient.cs b/Common/Common/Http/LCHttpClient.cs
index bcd61de..6fba2fa 100644
--- a/Common/Common/Http/LCHttpClient.cs
+++ b/Common/Common/Http/LCHttpClient.cs
@@ -27,6 +27,8 @@ namespace LeanCloud.Common {
 
         private Dictionary<string, Func<Task<string>>> runtimeHeaderTasks = new Dictionary<string, Func<Task<string>>>();
 
+        private Dictionary<string, string> additionalHeaders = new Dictionary<string, string>();
+
         public LCHttpClient(string appId, string appKey, string server, string sdkVersion, string apiVersion) {
             this.appId = appId;
             this.appKey = appKey;
@@ -44,7 +46,7 @@ namespace LeanCloud.Common {
         }
 
         public void AddRuntimeHeaderTask(string key, Func<Task<string>> task) {
-            if (key == null) {
+            if (string.IsNullOrEmpty(key)) {
                 return;
             }
             if (task == null) {
@@ -53,6 +55,16 @@ namespace LeanCloud.Common {
             runtimeHeaderTasks[key] = task;
         }
 
+        public void AddAddtionalHeader(string key, string value) {
+            if (string.IsNullOrEmpty(key)) {
+                return;
+            }
+            if (string.IsNullOrEmpty(value)) {
+                return;
+            }
+            additionalHeaders[key] = value;
+        }
+
         public Task<T> Get<T>(string path,
             Dictionary<string, object> headers = null,
             Dictionary<string, object> queryParams = null) {
@@ -141,10 +153,10 @@ namespace LeanCloud.Common {
             return url;
         }
 
-        async Task FillHeaders(HttpRequestHeaders headers, Dictionary<string, object> additionalHeaders = null) {
+        async Task FillHeaders(HttpRequestHeaders headers, Dictionary<string, object> reqHeaders = null) {
             // 额外 headers
-            if (additionalHeaders != null) {
-                foreach (KeyValuePair<string, object> kv in additionalHeaders) {
+            if (reqHeaders != null) {
+                foreach (KeyValuePair<string, object> kv in reqHeaders) {
                     headers.Add(kv.Key, kv.Value.ToString());
                 }
             }
@@ -159,8 +171,8 @@ namespace LeanCloud.Common {
                 string sign = $"{hash},{timestamp}";
                 headers.Add("X-LC-Sign", sign);
             }
-            if (LCCore.AdditionalHeaders.Count > 0) {
-                foreach (KeyValuePair<string, string> kv in LCCore.AdditionalHeaders) {
+            if (additionalHeaders.Count > 0) {
+                foreach (KeyValuePair<string, string> kv in additionalHeaders) {
                     headers.Add(kv.Key, kv.Value);
                 }    
             }
diff --git a/Common/Common/LCCore.cs b/Common/Common/LCCore.cs
index 4fb54e4..46bd4d6 100644
--- a/Common/Common/LCCore.cs
+++ b/Common/Common/LCCore.cs
@@ -44,10 +44,6 @@ namespace LeanCloud.Common {
             get; set;
         }
 
-        internal static Dictionary<string, string> AdditionalHeaders {
-            get;
-        } = new Dictionary<string, string>();
-
         public static void Initialize(string appId,
             string appKey,
             string server = null,
@@ -67,9 +63,5 @@ namespace LeanCloud.Common {
 
             HttpClient = new LCHttpClient(appId, appKey, server, SDKVersion, APIVersion);
         }
-
-        public static void AddHeader(string key, string value) {
-            AdditionalHeaders.Add(key, value);
-        }
     }
 }
diff --git a/Common/Common/Persistence/PersistenceController.cs b/Common/Common/Persistence/PersistenceController.cs
index 285d1c9..46a76c1 100644
--- a/Common/Common/Persistence/PersistenceController.cs
+++ b/Common/Common/Persistence/PersistenceController.cs
@@ -19,8 +19,6 @@ namespace LeanCloud.Common {
             }
 
             string path = GetFileFullPath(filename);
-            LCLogger.Debug($"WRITE: {path}");
-            LCLogger.Debug($"WRITE: {text}");
             using (FileStream fs = IOFile.OpenWrite(path)) {
                 byte[] buffer = Encoding.UTF8.GetBytes(text);
                 await fs.WriteAsync(buffer, 0, buffer.Length);
@@ -33,7 +31,6 @@ namespace LeanCloud.Common {
             }
 
             string path = GetFileFullPath(filename);
-            LCLogger.Debug($"READ: {path}");
             if (IOFile.Exists(path)) {
                 string text;
                 using (FileStream fs = IOFile.OpenRead(path)) {
@@ -41,7 +38,6 @@ namespace LeanCloud.Common {
                     await fs.ReadAsync(buffer, 0, (int)fs.Length);
                     text = Encoding.UTF8.GetString(buffer);
                 }
-                LCLogger.Debug($"READ: {text}");
                 return text;
             }
             return null;
diff --git a/Engine/Public/LCEngine.cs b/Engine/Public/LCEngine.cs
index d507196..a71368e 100644
--- a/Engine/Public/LCEngine.cs
+++ b/Engine/Public/LCEngine.cs
@@ -99,7 +99,7 @@ namespace LeanCloud.Engine {
             LCApplication.Initialize(Environment.GetEnvironmentVariable("LEANCLOUD_APP_ID"),
                 Environment.GetEnvironmentVariable("LEANCLOUD_APP_KEY"),
                 Environment.GetEnvironmentVariable("LEANCLOUD_API_SERVER"));
-            LCCore.AddHeader(LCHookKeyName, Environment.GetEnvironmentVariable("LEANCLOUD_APP_HOOK_KEY"));
+            LCCore.HttpClient.AddAddtionalHeader(LCHookKeyName, Environment.GetEnvironmentVariable("LEANCLOUD_APP_HOOK_KEY"));
 
             Assembly assembly = Assembly.GetCallingAssembly();
             ClassHooks = assembly.GetTypes()