diff --git a/docs/validator.md b/docs/validator.md
index aea5faf..e39af92 100644
--- a/docs/validator.md
+++ b/docs/validator.md
@@ -29,6 +29,7 @@ import (
 -   [IsAlpha](#IsAlpha)
 -   [IsAllUpper](#IsAllUpper)
 -   [IsAllLower](#IsAllLower)
+-   [IsASCII](#IsASCII)
 -   [IsBase64](#IsBase64)
 -   [IsChineseMobile](#IsChineseMobile)
 -   [IsChineseIdNum](#IsChineseIdNum)
@@ -293,6 +294,46 @@ func main() {
 }
 ```
 
+### <span id="IsASCII">IsASCII</span>
+
+<p>Checks if string is ASCII char.</p>
+
+<b>Signature:</b>
+
+```go
+func IsASCII(str string) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/validator"
+)
+
+func main() {
+    result1 := validator.IsASCII("ABC")
+    result2 := validator.IsASCII("123")
+    result3 := validator.IsASCII("")
+    result4 := validator.IsASCII("😄")
+    result5 := validator.IsASCII("你好")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+
+    // Output:
+    // true
+    // true
+    // true
+    // false
+    // false
+}
+```
+
 ### <span id="IsBase64">IsBase64</span>
 
 <p>Check if the string is base64 string.</p>
diff --git a/docs/validator_zh-CN.md b/docs/validator_zh-CN.md
index b89db00..41f8a01 100644
--- a/docs/validator_zh-CN.md
+++ b/docs/validator_zh-CN.md
@@ -29,6 +29,7 @@ import (
 -   [IsAlpha](#IsAlpha)
 -   [IsAllUpper](#IsAllUpper)
 -   [IsAllLower](#IsAllLower)
+-   [IsASCII](#IsASCII)
 -   [IsBase64](#IsBase64)
 -   [IsChineseMobile](#IsChineseMobile)
 -   [IsChineseIdNum](#IsChineseIdNum)
@@ -293,6 +294,46 @@ func main() {
 }
 ```
 
+### <span id="IsASCII">IsASCII</span>
+
+<p>验证字符串全部为ASCII字符。</p>
+
+<b>函数签名:</b>
+
+```go
+func IsASCII(str string) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/validator"
+)
+
+func main() {
+    result1 := validator.IsASCII("ABC")
+    result2 := validator.IsASCII("123")
+    result3 := validator.IsASCII("")
+    result4 := validator.IsASCII("😄")
+    result5 := validator.IsASCII("你好")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+
+    // Output:
+    // true
+    // true
+    // true
+    // false
+    // false
+}
+```
+
 ### <span id="IsBase64">IsBase64</span>
 
 <p>验证字符串是否是base64编码</p>
diff --git a/validator/validator.go b/validator/validator.go
index bd8ebef..4af7e08 100644
--- a/validator/validator.go
+++ b/validator/validator.go
@@ -58,6 +58,17 @@ func IsAllLower(str string) bool {
 	return str != ""
 }
 
+// IsASCII checks if string is ASCII char.
+// Play:
+func IsASCII(str string) bool {
+	for i := 0; i < len(str); i++ {
+		if str[i] > unicode.MaxASCII {
+			return false
+		}
+	}
+	return true
+}
+
 // ContainUpper check if the string contain at least one upper case letter A-Z.
 // Play: https://go.dev/play/p/CmWeBEk27-z
 func ContainUpper(str string) bool {
diff --git a/validator/validator_example_test.go b/validator/validator_example_test.go
index fe44731..482d262 100644
--- a/validator/validator_example_test.go
+++ b/validator/validator_example_test.go
@@ -407,3 +407,24 @@ func ExampleIsGBK() {
 	// Output:
 	// true
 }
+
+func ExampleIsASCII() {
+	result1 := IsASCII("ABC")
+	result2 := IsASCII("123")
+	result3 := IsASCII("")
+	result4 := IsASCII("😄")
+	result5 := IsASCII("你好")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+
+	// Output:
+	// true
+	// true
+	// true
+	// false
+	// false
+}
diff --git a/validator/validator_test.go b/validator/validator_test.go
index 34ba876..82dafcb 100644
--- a/validator/validator_test.go
+++ b/validator/validator_test.go
@@ -401,3 +401,13 @@ func TestIsGBK(t *testing.T) {
 	assert.Equal(true, IsGBK(gbkData))
 	assert.Equal(false, utf8.Valid(gbkData))
 }
+
+func TestIsASCII(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsASCII")
+
+	assert.Equal(true, IsASCII("ABC"))
+	assert.Equal(true, IsASCII("123"))
+	assert.Equal(true, IsASCII(""))
+	assert.Equal(false, IsASCII("😄"))
+	assert.Equal(false, IsASCII("你好"))
+}