After debugging for almost an afternoon, it was solved. Mainly because I do n’t know much about the principle. At first, I used Baidu directly. I wanted to find similar problems directly, but none of them. After reading some blogs and documents introduced by layui.msg (), it was solved. By debugging layui.verify, we know that after verification, it will jump to i.msg in form.js, so search for i.msg in from.js, and then add the level attribute.