diff --git "a/content/docs-lite/zh/docs/BriefTutorial/\345\207\275\346\225\260.md" "b/content/docs-lite/zh/docs/BriefTutorial/\345\207\275\346\225\260.md"
index 4aa1ccf68263c26851708cd4dcf0c3a63bacfb94..eab93e42d595723112371535bbbfdbd6b3a5a738 100644
--- "a/content/docs-lite/zh/docs/BriefTutorial/\345\207\275\346\225\260.md"
+++ "b/content/docs-lite/zh/docs/BriefTutorial/\345\207\275\346\225\260.md"
@@ -1003,6 +1003,85 @@ openGauss常用的函数如下：
     (1 row)
     ```
 
+-   cast\(x as y\)
+
+    描述：类型转换函数，将x转换成y指定的类型。
+
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('22-oct-1997' as timestamp);
+          timestamp      
+    ---------------------
+     1997-10-22 00:00:00
+    (1 row)
+    ```
+
+-   CAST( expr AS type_name [ DEFAULT return_value ON CONVERSION ERROR ][, fmt [, 'nlsparam' ] ])
+
+    描述：类型转换函数，将x转换成y指定的类型，并且支持DEFAULT设置默认值、fmt指定入参的输入格式以及nlsparam参数，目前nlsparam参数仅支持English和American。
+
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('12,454.8-' as numeric, '99G999D9S');
+     numeric
+    ----------
+     -12454.8
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('111111.111'+'1111' as numeric, '99G999D9S');
+      numeric
+    ------------
+     112222.111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('1e5'+'1111' as numeric, '999999.99');
+     numeric
+    ---------
+      101111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('此参数错误' as numeric default 321456231 on conversion error, '999,999,999,999.99');
+      numeric
+    -----------
+     321456231
+    (1 row)
+    ```
+
+    ```
+    openGauss=#  SELECT cast('12-sep-2014' as timestamp , 'DD-Mon-YYYY');
+          timestamp      
+    ---------------------
+     2014-09-12 00:00:00
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('此为错误输入' as timestamp DEFAULT '11-01-11 14:10:10.123000' ON CONVERSION ERROR,'DD-MM-RR HH24:MI:SS.FF');
+            timestamp        
+    -------------------------
+     2011-11-01 14:10:10.123
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('01-Jan-03 14:10:10.123000' as timestamp DEFAULT '11-Jan-11 14:10:10.123000' ON CONVERSION ERROR,'DD-Mon-RR HH24:MI:SS.FF','NLS_DATE_LANGUAGE = American');
+            timestamp        
+    -------------------------
+     2003-01-01 14:10:10.123
+    (1 row)
+    ```
 
 -   to\_hex\(number int or bigint\)
 
diff --git "a/content/docs-lite/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md" "b/content/docs-lite/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md"
index 3462c8614bff081f2f6e860501d2ab7a09de7a95..0445bf71953df9d120cc40a7e413af6d6201d600 100644
--- "a/content/docs-lite/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md"
+++ "b/content/docs-lite/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md"
@@ -144,6 +144,86 @@
   (1 row)
   ```
 
+-   cast\(x as y\)
+
+    描述：类型转换函数，将x转换成y指定的类型。
+
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('22-oct-1997' as timestamp);
+          timestamp      
+    ---------------------
+     1997-10-22 00:00:00
+    (1 row)
+    ```
+
+-   CAST( expr AS type_name [ DEFAULT return_value ON CONVERSION ERROR ][, fmt [, 'nlsparam' ] ])
+
+    描述：类型转换函数，将x转换成y指定的类型，并且支持DEFAULT设置默认值、fmt指定入参的输入格式以及nlsparam参数，目前nlsparam参数仅支持English和American。
+
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('12,454.8-' as numeric, '99G999D9S');
+     numeric
+    ----------
+     -12454.8
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('111111.111'+'1111' as numeric, '99G999D9S');
+      numeric
+    ------------
+     112222.111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('1e5'+'1111' as numeric, '999999.99');
+     numeric
+    ---------
+      101111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('此参数错误' as numeric default 321456231 on conversion error, '999,999,999,999.99');
+      numeric
+    -----------
+     321456231
+    (1 row)
+    ```
+
+    ```
+    openGauss=#  SELECT cast('12-sep-2014' as timestamp , 'DD-Mon-YYYY');
+          timestamp      
+    ---------------------
+     2014-09-12 00:00:00
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('此为错误输入' as timestamp DEFAULT '11-01-11 14:10:10.123000' ON CONVERSION ERROR,'DD-MM-RR HH24:MI:SS.FF');
+            timestamp        
+    -------------------------
+     2011-11-01 14:10:10.123
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('01-Jan-03 14:10:10.123000' as timestamp DEFAULT '11-Jan-11 14:10:10.123000' ON CONVERSION ERROR,'DD-Mon-RR HH24:MI:SS.FF','NLS_DATE_LANGUAGE = American');
+            timestamp        
+    -------------------------
+     2003-01-01 14:10:10.123
+    (1 row)
+    ```
+
 -   to\_char\(datetime/interval \[, fmt\]\)
 
     描述：将一个DATE、TIMESTAMP、TIMESTAMP WITH TIME ZONE或者TIMESTAMP WITH LOCAL TIME ZONE类型的DATETIME或者INTERVAL值按照fmt指定的格式转换为TEXT类型。
diff --git "a/content/zh/docs/BriefTutorial/\345\207\275\346\225\260.md" "b/content/zh/docs/BriefTutorial/\345\207\275\346\225\260.md"
index 7c03d565359f86d02e0a12c1944c9b1d0adb5c95..5b9bdae4d51ac7e7c579644caa82d61a155d46e0 100644
--- "a/content/zh/docs/BriefTutorial/\345\207\275\346\225\260.md"
+++ "b/content/zh/docs/BriefTutorial/\345\207\275\346\225\260.md"
@@ -1002,6 +1002,85 @@ openGauss常用的函数如下：
     (1 row)
     ```
 
+-   cast\(x as y\)
+
+    描述：类型转换函数，将x转换成y指定的类型。
+
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('22-oct-1997' as timestamp);
+          timestamp      
+    ---------------------
+     1997-10-22 00:00:00
+    (1 row)
+    ```
+
+-   CAST( expr AS type_name [ DEFAULT return_value ON CONVERSION ERROR ][, fmt [, 'nlsparam' ] ])
+
+    描述：类型转换函数，将x转换成y指定的类型，并且支持DEFAULT设置默认值、fmt指定入参的输入格式以及nlsparam参数，目前nlsparam参数仅支持English和American。
+
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('12,454.8-' as numeric, '99G999D9S');
+     numeric
+    ----------
+     -12454.8
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('111111.111'+'1111' as numeric, '99G999D9S');
+      numeric
+    ------------
+     112222.111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('1e5'+'1111' as numeric, '999999.99');
+     numeric
+    ---------
+      101111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('此参数错误' as numeric default 321456231 on conversion error, '999,999,999,999.99');
+      numeric
+    -----------
+     321456231
+    (1 row)
+    ```
+
+    ```
+    openGauss=#  SELECT cast('12-sep-2014' as timestamp , 'DD-Mon-YYYY');
+          timestamp      
+    ---------------------
+     2014-09-12 00:00:00
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('此为错误输入' as timestamp DEFAULT '11-01-11 14:10:10.123000' ON CONVERSION ERROR,'DD-MM-RR HH24:MI:SS.FF');
+            timestamp        
+    -------------------------
+     2011-11-01 14:10:10.123
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('01-Jan-03 14:10:10.123000' as timestamp DEFAULT '11-Jan-11 14:10:10.123000' ON CONVERSION ERROR,'DD-Mon-RR HH24:MI:SS.FF','NLS_DATE_LANGUAGE = American');
+            timestamp        
+    -------------------------
+     2003-01-01 14:10:10.123
+    (1 row)
+    ```
 
 -   to\_hex\(number int or bigint\)
 
diff --git "a/content/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md" "b/content/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md"
index 03864edadf352572a0fdda87514a2cdafa6822a7..3267a29813474888ebc24bcf02d21c1c693981ac 100644
--- "a/content/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md"
+++ "b/content/zh/docs/SQLReference/\347\261\273\345\236\213\350\275\254\346\215\242\345\207\275\346\225\260.md"
@@ -19,6 +19,8 @@
 -   cast\(x as y\)
 
     描述：类型转换函数，将x转换成y指定的类型。
+    
+    返回值类型：type_name
 
     示例：
 
@@ -30,6 +32,70 @@
     (1 row)
     ```
 
+-   CAST( expr AS type_name [ DEFAULT return_value ON CONVERSION ERROR ][, fmt [, 'nlsparam' ] ])
+
+    描述：类型转换函数，将x转换成y指定的类型，并且支持DEFAULT设置默认值、fmt指定入参的输入格式以及nlsparam参数，目前nlsparam参数仅支持English和American。
+    
+    返回值类型：type_name
+
+    示例：
+
+    ```
+    openGauss=# SELECT cast('12,454.8-' as numeric, '99G999D9S');
+     numeric
+    ----------
+     -12454.8
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('111111.111'+'1111' as numeric, '99G999D9S');
+      numeric
+    ------------
+     112222.111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('1e5'+'1111' as numeric, '999999.99');
+     numeric
+    ---------
+      101111
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast('此参数错误' as numeric default 321456231 on conversion error, '999,999,999,999.99');
+      numeric
+    -----------
+     321456231
+    (1 row)
+    ```
+
+    ```
+    openGauss=#  SELECT cast('12-sep-2014' as timestamp , 'DD-Mon-YYYY');
+          timestamp      
+    ---------------------
+     2014-09-12 00:00:00
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('此为错误输入' as timestamp DEFAULT '11-01-11 14:10:10.123000' ON CONVERSION ERROR,'DD-MM-RR HH24:MI:SS.FF');
+            timestamp        
+    -------------------------
+     2011-11-01 14:10:10.123
+    (1 row)
+    ```
+
+    ```
+    openGauss=# SELECT cast ('01-Jan-03 14:10:10.123000' as timestamp DEFAULT '11-Jan-11 14:10:10.123000' ON CONVERSION ERROR,'DD-Mon-RR HH24:MI:SS.FF','NLS_DATE_LANGUAGE = American');
+            timestamp        
+    -------------------------
+     2003-01-01 14:10:10.123
+    (1 row)
+    ```
+
 -   hextoraw\(raw\)
 
     描述：将一个十六进制构成的字符串转换为raw类型。