diff --git a/include/cos_config.h b/include/cos_config.h
index 14eef56..2679cfa 100644
--- a/include/cos_config.h
+++ b/include/cos_config.h
@@ -25,6 +25,7 @@ class CosConfig {
         m_secret_key(""),
         m_region(""),
         m_tmp_token(""),
+        m_set_intranet_once(false),
         m_is_use_intranet(false),
         m_intranet_addr(""),
         m_config_parsed(false) {}
@@ -42,6 +43,7 @@ class CosConfig {
         m_secret_key(secret_key),
         m_region(region),
         m_tmp_token(""),
+        m_set_intranet_once(false),
         m_is_use_intranet(false),
         m_intranet_addr(""),
         m_config_parsed(false) {}
@@ -60,6 +62,7 @@ class CosConfig {
         m_secret_key(secret_key),
         m_region(region),
         m_tmp_token(tmp_token),
+        m_set_intranet_once(false),
         m_is_use_intranet(false),
         m_intranet_addr(""),
         m_config_parsed(false) {}
@@ -73,6 +76,7 @@ class CosConfig {
     m_secret_key = config.m_secret_key;
     m_region = config.m_region;
     m_tmp_token = config.m_tmp_token;
+    m_set_intranet_once = config.m_set_intranet_once;
     m_is_use_intranet = config.m_is_use_intranet;
     m_intranet_addr = config.m_intranet_addr;
     m_config_parsed = config.m_config_parsed;
@@ -87,6 +91,7 @@ class CosConfig {
     m_secret_key = config.m_secret_key;
     m_region = config.m_region;
     m_tmp_token = config.m_tmp_token;
+    m_set_intranet_once = config.m_set_intranet_once;
     m_is_use_intranet = config.m_is_use_intranet;
     m_intranet_addr = config.m_intranet_addr;
     m_config_parsed = config.m_config_parsed;
@@ -159,6 +164,8 @@ class CosConfig {
 
   std::string GetIntranetAddr();
 
+  bool GetSetIntranetOnce() const {return m_set_intranet_once;}
+
   /// \brief 设置日志回调
   void SetLogCallback(const LogCallback log_callback);
 
@@ -179,6 +186,7 @@ class CosConfig {
   std::string m_region;
   std::string m_tmp_token;
 
+  bool m_set_intranet_once;
   bool m_is_use_intranet;
   std::string m_intranet_addr;
   bool m_config_parsed;
diff --git a/include/cos_defines.h b/include/cos_defines.h
index 00c32c6..9479e78 100644
--- a/include/cos_defines.h
+++ b/include/cos_defines.h
@@ -11,7 +11,7 @@
 
 namespace qcloud_cos {
 
-#define COS_CPP_SDK_VERSON "v5.5.6"
+#define COS_CPP_SDK_VERSON "v5.5.7"
 
 /// 路径分隔符
 const std::string kPathDelimiter = "/";
diff --git a/src/cos_config.cpp b/src/cos_config.cpp
index 033dc00..fae2a4a 100644
--- a/src/cos_config.cpp
+++ b/src/cos_config.cpp
@@ -15,6 +15,7 @@ CosConfig::CosConfig(const std::string& config_file)
       m_secret_key(""),
       m_region(""),
       m_tmp_token(""),
+      m_set_intranet_once(false),
       m_is_use_intranet(false),
       m_intranet_addr(""),
       m_config_parsed(false) {
@@ -191,11 +192,13 @@ bool CosConfig::InitConf(const std::string& config_file) {
   if (JsonObjectGetBoolValue(object, "IsUseIntranet", &bool_value)) {
     CosSysConfig::SetIsUseIntranet(bool_value);
     m_is_use_intranet = bool_value;
+    m_set_intranet_once = true;
   }
 
   if (JsonObjectGetStringValue(object, "IntranetAddr", &str_value)) {
     CosSysConfig::SetIntranetAddr(str_value);
     m_intranet_addr = str_value;
+    m_set_intranet_once = true;
   }
 
   CosSysConfig::PrintValue();
@@ -236,6 +239,8 @@ void CosConfig::SetConfigCredentail(const std::string& access_key,
 void CosConfig::SetIsUseIntranetAddr(bool is_use_intranet) {
   CosSysConfig::SetIsUseIntranet(is_use_intranet);
   m_is_use_intranet = is_use_intranet;
+
+  m_set_intranet_once = true;
 }
 
 bool CosConfig::IsUseIntranet() {
@@ -245,6 +250,8 @@ bool CosConfig::IsUseIntranet() {
 void CosConfig::SetIntranetAddr(const std::string& intranet_addr) {
   CosSysConfig::SetIntranetAddr(intranet_addr);
   m_intranet_addr = intranet_addr;
+
+  m_set_intranet_once = true;
 }
 
 std::string CosConfig::GetIntranetAddr() {
diff --git a/src/cos_sys_config.cpp b/src/cos_sys_config.cpp
index e0afb73..6e7fcd7 100644
--- a/src/cos_sys_config.cpp
+++ b/src/cos_sys_config.cpp
@@ -57,6 +57,8 @@ unsigned CosSysConfig::m_dns_cache_expire_seconds = 600;
 // dns cache大小
 unsigned CosSysConfig::m_dns_cache_size = 1000;
 
+std::mutex m_intranet_addr_lock;
+
 void CosSysConfig::PrintValue() {
   std::cout << "upload_part_size:" << m_upload_part_size << std::endl;
   std::cout << "upload_copy_part_size:" << m_upload_copy_part_size << std::endl;
@@ -213,6 +215,7 @@ void CosSysConfig::SetIsUseIntranet(bool is_use_intranet) {
 bool CosSysConfig::IsUseIntranet() { return m_is_use_intranet; }
 
 void CosSysConfig::SetIntranetAddr(const std::string& intranet_addr) {
+  std::lock_guard<std::mutex> lock(m_intranet_addr_lock);
   m_intranet_addr = intranet_addr;
 }
 
@@ -248,7 +251,10 @@ std::string CosSysConfig::GetCIHost(const std::string& bucket_name,
 
 std::string CosSysConfig::GetDestDomain() { return m_dest_domain; }
 
-std::string CosSysConfig::GetIntranetAddr() { return m_intranet_addr; }
+std::string CosSysConfig::GetIntranetAddr() { 
+  std::lock_guard<std::mutex> lock(m_intranet_addr_lock);
+  return m_intranet_addr; 
+}
 
 LogCallback CosSysConfig::GetLogCallback() { return m_log_callback; }
 
diff --git a/src/op/base_op.cpp b/src/op/base_op.cpp
index bf39273..143ec32 100644
--- a/src/op/base_op.cpp
+++ b/src/op/base_op.cpp
@@ -305,9 +305,13 @@ std::string BaseOp::GetRealUrl(const std::string& host, const std::string& path,
     dest_path = "/" + dest_path;
   }
 
-  if (m_config->IsUseIntranet() &&
+  if (m_config->GetSetIntranetOnce() &&
+      m_config->IsUseIntranet() &&
       !m_config->GetIntranetAddr().empty()) {
     dest_host = m_config->GetIntranetAddr();
+  } else if (CosSysConfig::IsUseIntranet() &&
+      !CosSysConfig::GetIntranetAddr().empty()) {
+    dest_host = CosSysConfig::GetIntranetAddr();
   } else if (!CosSysConfig::GetDestDomain().empty()) {
     dest_host = CosSysConfig::GetDestDomain();
   } else if (CosSysConfig::GetUseDnsCache()) {