diff --git a/cross-platform/Android/README.md b/cross-platform/Android/README.md
index 91e77723ef1..1605b8277ac 100644
--- a/cross-platform/Android/README.md
+++ b/cross-platform/Android/README.md
@@ -2,4 +2,4 @@
 
 ## 下载地址
 
-[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.15/cross-platform/TIM_Cross_Platform_Android_latest.zip)
+[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.45/cross-platform/TIM_Cross_Platform_Android_latest.zip)
diff --git a/cross-platform/Mac/README.md b/cross-platform/Mac/README.md
index 8b837c68522..4b87e5d8962 100644
--- a/cross-platform/Mac/README.md
+++ b/cross-platform/Mac/README.md
@@ -2,4 +2,4 @@
 
 ## 下载地址
 
-[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.15/cross-platform/TIM_Cross_Platform_Mac_latest.zip)
+[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.45/cross-platform/TIM_Cross_Platform_Mac_latest.zip)
diff --git a/cross-platform/Windows/README.md b/cross-platform/Windows/README.md
index 8fe2b85731a..ab06d9f4c78 100644
--- a/cross-platform/Windows/README.md
+++ b/cross-platform/Windows/README.md
@@ -2,7 +2,7 @@
 
 ## 下载地址
 
-[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.15/cross-platform/TIM_Cross_Platform_Windows_latest.zip)
+[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.45/cross-platform/TIM_Cross_Platform_Windows_latest.zip)
 
 ## TIMSDK for Windows
 
diff --git a/cross-platform/iOS/README.md b/cross-platform/iOS/README.md
index 643f0437c7d..59851fe8b29 100644
--- a/cross-platform/iOS/README.md
+++ b/cross-platform/iOS/README.md
@@ -2,4 +2,4 @@
 
 ## 下载地址
 
-[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.15/cross-platform/TIM_Cross_Platform_iOS_latest.zip)
+[最新C接口下载](https://imsdk-1252463788.cos.ap-guangzhou.myqcloud.com/4.5.45/cross-platform/TIM_Cross_Platform_iOS_latest.zip)