修改this.$alert 消息弹出框的宽度

 this.$alert(`${res.data.msg}`, {
            dangerouslyUseHTMLString: true,
            distinguishCancelAndClose: true,
            closeOnClickModal: true,
            showConfirmButton: false,
            showClose: false,
            type: "error",
         });

需要写在没有scope的style标签内

<style>
.el-message-box {
  width: 600px;
}
</style>