diff --git a/utils/str/str.go b/utils/str/str.go
index 33e8d7b..9dc2fa2 100644
--- a/utils/str/str.go
+++ b/utils/str/str.go
@@ -19,11 +19,11 @@ var (
 // FirstUpper 首字母大写
 func FirstUpper(str string) string {
 	var upperStr string
-	vv := []rune(str) // 后文有介绍
+	vv := []rune(str)
 	for i := 0; i < len(vv); i++ {
 		if i == 0 {
-			if vv[i] >= 97 && vv[i] <= 122 { // 后文有介绍
-				vv[i] -= 32 // string的码表相差32位
+			if vv[i] >= 97 && vv[i] <= 122 {
+				vv[i] -= 32
 				upperStr += string(vv[i])
 			} else {
 				return str
@@ -34,3 +34,151 @@ func FirstUpper(str string) string {
 	}
 	return upperStr
 }
+
+// FirstLower 首字母小写
+func FirstLower(str string) string {
+	var lowerStr string
+	vv := []rune(str)
+	for i := 0; i < len(vv); i++ {
+		if i == 0 {
+			if vv[i] >= 65 && vv[i] <= 90 {
+				vv[i] += 32
+				lowerStr += string(vv[i])
+			} else {
+				return str
+			}
+		} else {
+			lowerStr += string(vv[i])
+		}
+	}
+	return lowerStr
+}
+
+// FirstUpperBytes 首字母大写
+func FirstUpperBytes(str []byte) []byte {
+	var upperStr []byte
+	vv := []rune(string(str))
+	for i := 0; i < len(vv); i++ {
+		if i == 0 {
+			if vv[i] >= 97 && vv[i] <= 122 {
+				vv[i] -= 32
+				upperStr = append(upperStr, string(vv[i])...)
+			} else {
+				return str
+			}
+		} else {
+			upperStr = append(upperStr, string(vv[i])...)
+		}
+	}
+	return upperStr
+}
+
+// FirstLowerBytes 首字母小写
+func FirstLowerBytes(str []byte) []byte {
+	var lowerStr []byte
+	vv := []rune(string(str))
+	for i := 0; i < len(vv); i++ {
+		if i == 0 {
+			if vv[i] >= 65 && vv[i] <= 90 {
+				vv[i] += 32
+				lowerStr = append(lowerStr, string(vv[i])...)
+			} else {
+				return str
+			}
+		} else {
+			lowerStr = append(lowerStr, string(vv[i])...)
+		}
+	}
+	return lowerStr
+}
+
+// IsEmpty 判断字符串是否为空
+func IsEmpty(str string) bool {
+	return len(str) == 0
+}
+
+// IsEmptyBytes 判断字符串是否为空
+func IsEmptyBytes(str []byte) bool {
+	return len(str) == 0
+}
+
+// IsNotEmpty 判断字符串是否不为空
+func IsNotEmpty(str string) bool {
+	return !IsEmpty(str)
+}
+
+// IsNotEmptyBytes 判断字符串是否不为空
+func IsNotEmptyBytes(str []byte) bool {
+	return !IsEmptyBytes(str)
+}
+
+// SnakeString 蛇形字符串
+func SnakeString(str string) string {
+	var snakeStr string
+	vv := []rune(str)
+	for i := 0; i < len(vv); i++ {
+		if vv[i] >= 65 && vv[i] <= 90 {
+			vv[i] += 32
+			snakeStr += "_" + string(vv[i])
+		} else {
+			snakeStr += string(vv[i])
+		}
+	}
+	return snakeStr
+}
+
+// SnakeStringBytes 蛇形字符串
+func SnakeStringBytes(str []byte) []byte {
+	var snakeStr []byte
+	vv := []rune(string(str))
+	for i := 0; i < len(vv); i++ {
+		if vv[i] >= 65 && vv[i] <= 90 {
+			vv[i] += 32
+			snakeStr = append(snakeStr, '_')
+			snakeStr = append(snakeStr, string(vv[i])...)
+		} else {
+			snakeStr = append(snakeStr, string(vv[i])...)
+		}
+	}
+	return snakeStr
+}
+
+// CamelString 驼峰字符串
+func CamelString(str string) string {
+	var camelStr string
+	vv := []rune(str)
+	for i := 0; i < len(vv); i++ {
+		if vv[i] == '_' {
+			i++
+			if vv[i] >= 97 && vv[i] <= 122 {
+				vv[i] -= 32
+				camelStr += string(vv[i])
+			} else {
+				return str
+			}
+		} else {
+			camelStr += string(vv[i])
+		}
+	}
+	return camelStr
+}
+
+// CamelStringBytes 驼峰字符串
+func CamelStringBytes(str []byte) []byte {
+	var camelStr []byte
+	vv := []rune(string(str))
+	for i := 0; i < len(vv); i++ {
+		if vv[i] == '_' {
+			i++
+			if vv[i] >= 97 && vv[i] <= 122 {
+				vv[i] -= 32
+				camelStr = append(camelStr, string(vv[i])...)
+			} else {
+				return str
+			}
+		} else {
+			camelStr = append(camelStr, string(vv[i])...)
+		}
+	}
+	return camelStr
+}