这个样式比较简单，直接在需要验证码的地方添加就行了。如果这个页面比较复杂，用组件会比较好。

<template><div class="join_formitem"><label class="enquiry">验证码<span>:</span></label><div class="captcha"><input type="text" placeholder="请输入验证码" class="yanzhengma_input" v-model="picLyanzhengma" /><input type="button" @click="createdCode" class="verification" v-model="checkCode" /></div></div>
</template><script>
export default {data(){return{code:'',checkCode:'',                   picLyanzhengma:''         //..验证码图片}},created(){this.createdCode()},methods: {// 图片验证码createdCode(){// 先清空验证码输入this.code = ""this.checkCode = ""this.picLyanzhengma = ""// 验证码长度const codeLength = 4// 随机数const random = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z')for(let i = 0;i < codeLength;i++){// 取得随机数的索引(0~35)let index = Math.floor(Math.random() * 36)// 根据索引取得随机数加到code上this.code += random[index]}// 把code值赋给验证码this.checkCode = this.code}}
}
</script><style>
.yanzhengma_input{font-family: 'Exo 2',sans-serif;border: 1px solid #fff;color: #fff;outline: none;border-radius: 12px;letter-spacing: 1px;font-size: 17px;font-weight: normal;background-color: rgba(82,56,76,.15);padding: 5px 0 5px 10px;margin-left: 30px;height: 30px;margin-top: 25px;border: 1px solid #e6e6e6;
}
.verification{border-radius: 12px;width: 100px;letter-spacing: 5px;margin-left: 50px;height: 40px;transform: translate(-15px,0);
}
.captcha{height:50px;text-align: justify;
}
</style>

效果：

1. 新建一个文件夹 verificationCode（文件夹随便自己命名），然后在该文件下新建一个 index.vue，复制下面的代码：

<template><div class="ValidCode disabled-select" :style="`width:${width}; height:${height}`" @click="refreshCode"><span v-for="(item, index) in codeList" :key="index" :style="getStyle(item)">{{item.code}}</span></div>
</template><script>
export default {name: 'validCode',props: {width: {type: String,default: '100px'},height: {type: String,default: '48px'},length: {type: Number,default: 4}},data () {return {codeList: []}},mounted () {this.createdCode()},methods: {//刷新验证码的方法refreshCode () {this.createdCode()},// 生成验证码的方法createdCode () {let len = this.length,codeList = [],chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz0123456789',charsLen = chars.length// 生成for (let i = 0; i < len; i++) {let rgb = [Math.round(Math.random() * 220), Math.round(Math.random() * 240), Math.round(Math.random() * 200)]codeList.push({code: chars.charAt(Math.floor(Math.random() * charsLen)),color: `rgb(${rgb})`,fontSize: `1${[Math.floor(Math.random() * 10)]}px`,padding: `${[Math.floor(Math.random() * 10)]}px`,transform: `rotate(${Math.floor(Math.random() * 90) - Math.floor(Math.random() * 90)}deg)`})}// 指向this.codeList = codeList;// 将当前数据派发出去// this.$emit('update:value', codeList.map(item => item.code).join(''))this.$emit('sendData', codeList.map(item => item.code).join(''));//this.$emit('暴露给父组件的方法名',携带的参数); //记住你命名的这个方法},// 每个元素生成动态的样式getStyle (data) {return `color: ${data.color}; font-size: ${data.fontSize}; padding: ${data.padding}; transform: ${data.transform}`}}
}
</script><style scoped lang="scss">.ValidCode{display: flex;justify-content: center;align-items: center;cursor: pointer;span{display: inline-block;}}
</style>

2. 在父组件中使用

<validCode v-model="validCode" @sendData="getCode"></validCode>//在<script>下面引入组件
import validCode from '@/components/verificationCode'data(){return{validCode:""}
},
methods:{
//在方法中获取验证码的数据
//从子组件获取验证码，并将验证码返回到页面getCode(data){console.log(data)this.validCode = data;//在data中定义一个 validCode:'',用来记录验证码。}
}

3. 鉴于有的小伙伴需要，第三步就贴全部代码吧。

<el-form :model="loginForm" :rules="rules" ref="loginForm"class="demo-ruleForm login-form"><el-form-item prop="userName"><el-input v-model="loginForm.userName" style="width:418px" placeholder="输入您的账号或手机号" class="nobr" size="meddle" autocomplete="off"></el-input></el-form-item><el-form-item prop="password"><el-input show-password v-model="loginForm.password" style="width:418px" placeholder="输入您的密码" class="nobr" autocomplete="off"></el-input></el-form-item><el-form-item required><el-col :span="18"><el-form-item prop="validCode"><el-input v-model="loginForm.validCode" style="width:313px" placeholder="输入验证码（忽略大小写）" class="nobr"></el-input></el-form-item>                </el-col><el-col :span="6" align="right"><validCode v-model="validCode" ref="refresh" @sendData="getCode"></validCode></el-col></el-form-item>  <el-form-item><el-button type="primary" class="nobr" style="width:418px;" @click="submitForm('loginForm')">登录</el-button></el-form-item>
</el-form><script>
import validCode from '@/components/verificationCode'data(){let validUserName = (rule,value,callback) =>{if(!value){return callback(new Error('用户名不能为空'));} else {callback();}}let validPassword = (rule,value,callback) =>{if(!value){return callback(new Error('密码不能为空'));} else{callback();}}const checkValidCode = (rule, value, callback) => {if (!value) {callback(new Error('请输入验证码'))} else if (value.toUpperCase() !== this.validCode.toUpperCase()) {callback(new Error('验证码不正确'))} else {callback()}}return {validCode:"",loginForm:{userName: "",password: ""},rules:{userName:[{ validator: validUserName, trigger: 'blur' }],password:[{ validator: validPassword, trigger: 'blur' }],validCode:[{ validator: checkValidCode, trigger: 'blur' }]}}
},  methods:{submitForm(formName){this.$refs[formName].validate((valid) => {if (valid) {//调用录接口//如果登录失败，需要刷新验证码的this.$refs.refresh.createdCode();this.validCode = ""; //清空验证码输入框的内容} else {console.log('error submit!!');return false;}});},//从子组件获取验证码，并将验证码返回到页面getCode(data){// console.log(data)this.validCode = data;}
</script>