let pattern = new RegExp("[\u4E00-\u9FA5]+");
let str='12'
if (pattern.test(str)) {
return this.$message({
message: "字符串不能是中文",
type: "warning",
});
}
<input type="text" size="60" onkeyup="this.value=this.value.replace(/[\u4E00-\u9FA5]+/,'')">