diff --git a/docs/table-design/index/prefix-index.md b/docs/table-design/index/prefix-index.md
index 7801c9fce6138..a1eea2c7c8c88 100644
--- a/docs/table-design/index/prefix-index.md
+++ b/docs/table-design/index/prefix-index.md
@@ -52,7 +52,7 @@ Since the KEY definition of a table is unique, a table can only have one type of
 
 ## Syntax
 
-There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index.
+There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index. If the prefix index encounters a varchar field, it automatically truncates the first 20 bytes.
 
 ## Example Usage
 
diff --git a/i18n/zh-CN/docusaurus-plugin-content-docs/current/table-design/index/prefix-index.md b/i18n/zh-CN/docusaurus-plugin-content-docs/current/table-design/index/prefix-index.md
index f138bcf35ac58..b68c6d55a2b24 100644
--- a/i18n/zh-CN/docusaurus-plugin-content-docs/current/table-design/index/prefix-index.md
+++ b/i18n/zh-CN/docusaurus-plugin-content-docs/current/table-design/index/prefix-index.md
@@ -51,7 +51,7 @@ Apache Doris 的数据存储在类似 SSTable（Sorted String Table）的数据
 
 ## 使用语法
 
-前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。
+前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。如果前缀索引碰见varchar类型的字段，会自动截断前20个字节。
 
 
 ## 使用示例
diff --git a/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.0/table-design/index/prefix-index.md b/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.0/table-design/index/prefix-index.md
index c32e8d845c1c3..ee1d0c7fcd521 100644
--- a/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.0/table-design/index/prefix-index.md
+++ b/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.0/table-design/index/prefix-index.md
@@ -51,7 +51,7 @@ Apache Doris 的数据存储在类似 SSTable（Sorted String Table）的数据
 
 ## 使用语法
 
-前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。
+前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。如果前缀索引碰见varchar类型的字段，会自动截断前20个字节。
 
 
 ## 使用示例
diff --git a/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.1/table-design/index/prefix-index.md b/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.1/table-design/index/prefix-index.md
index c32e8d845c1c3..ee1d0c7fcd521 100644
--- a/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.1/table-design/index/prefix-index.md
+++ b/i18n/zh-CN/docusaurus-plugin-content-docs/version-2.1/table-design/index/prefix-index.md
@@ -51,7 +51,7 @@ Apache Doris 的数据存储在类似 SSTable（Sorted String Table）的数据
 
 ## 使用语法
 
-前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。
+前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。如果前缀索引碰见varchar类型的字段，会自动截断前20个字节。
 
 
 ## 使用示例
diff --git a/i18n/zh-CN/docusaurus-plugin-content-docs/version-3.0/table-design/index/prefix-index.md b/i18n/zh-CN/docusaurus-plugin-content-docs/version-3.0/table-design/index/prefix-index.md
index f138bcf35ac58..b68c6d55a2b24 100644
--- a/i18n/zh-CN/docusaurus-plugin-content-docs/version-3.0/table-design/index/prefix-index.md
+++ b/i18n/zh-CN/docusaurus-plugin-content-docs/version-3.0/table-design/index/prefix-index.md
@@ -51,7 +51,7 @@ Apache Doris 的数据存储在类似 SSTable（Sorted String Table）的数据
 
 ## 使用语法
 
-前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。
+前缀索引没有专门的语法去定义，建表时自动取表的 Key 的前 36 字节作为前缀索引。如果前缀索引碰见varchar类型的字段，会自动截断前20个字节。
 
 
 ## 使用示例
diff --git a/versioned_docs/version-2.0/table-design/index/prefix-index.md b/versioned_docs/version-2.0/table-design/index/prefix-index.md
index 7801c9fce6138..a1eea2c7c8c88 100644
--- a/versioned_docs/version-2.0/table-design/index/prefix-index.md
+++ b/versioned_docs/version-2.0/table-design/index/prefix-index.md
@@ -52,7 +52,7 @@ Since the KEY definition of a table is unique, a table can only have one type of
 
 ## Syntax
 
-There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index.
+There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index. If the prefix index encounters a varchar field, it automatically truncates the first 20 bytes.
 
 ## Example Usage
 
diff --git a/versioned_docs/version-2.1/table-design/index/prefix-index.md b/versioned_docs/version-2.1/table-design/index/prefix-index.md
index 7801c9fce6138..a1eea2c7c8c88 100644
--- a/versioned_docs/version-2.1/table-design/index/prefix-index.md
+++ b/versioned_docs/version-2.1/table-design/index/prefix-index.md
@@ -52,7 +52,7 @@ Since the KEY definition of a table is unique, a table can only have one type of
 
 ## Syntax
 
-There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index.
+There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index. If the prefix index encounters a varchar field, it automatically truncates the first 20 bytes.
 
 ## Example Usage
 
diff --git a/versioned_docs/version-3.0/table-design/index/prefix-index.md b/versioned_docs/version-3.0/table-design/index/prefix-index.md
index 7801c9fce6138..a1eea2c7c8c88 100644
--- a/versioned_docs/version-3.0/table-design/index/prefix-index.md
+++ b/versioned_docs/version-3.0/table-design/index/prefix-index.md
@@ -52,7 +52,7 @@ Since the KEY definition of a table is unique, a table can only have one type of
 
 ## Syntax
 
-There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index.
+There is no specific syntax for defining a prefix index. When creating a table, the first 36 bytes of the table's KEY are automatically taken as the prefix index. If the prefix index encounters a varchar field, it automatically truncates the first 20 bytes.
 
 ## Example Usage