el-radio-group 组件方法：

<template><el-radio-group v-model="radio"><el-radio :value="0">阶梯达标</el-radio><el-radio :value="1">限时达标</el-radio></el-radio-group>
</template>

给radio添加监听事件 @change：

<template><el-radio-group v-model="radio" @change="handleChange"><el-radio :value="0">阶梯达标</el-radio><el-radio :value="1">限时达标</el-radio></el-radio-group>
</template>

这里也可以使用字典：

               <el-radio-group v-model="form.stageType" @change="handleChange"><el-radiov-for="dict in stage_type":key="dict.value":label="dict.value">{{ dict.label }}</el-radio></el-radio-group>

点击某一项的时候，根据点击事件修改current的值。

<script setup name="Rewards">const current = ref(0);const handleChange = (val) => {current.value = val;}
</script>

使用v-if 判断radio回显内容：

       <div class="con"><div class="con-item" v-if="current == 0"><div class="input-items"><label for="name">达标交易量：</label><inputtype="text"placeholder="输入交易量"/></div></div><div class="con-item" v-if="current == 1"><div class="input-items"><label for="name">开通后（天）：</label><inputtype="text"placeholder="输入天数"/></div></div></div>

实现效果：

完整代码：

    <!-- 添加或修改阶段奖励对话框 --><el-dialog :title="title" v-model="open" width="1000px" append-to-body><el-form ref="rewardsRef" :model="form" :rules="rules" label-width="100px"><el-form-item label="模板名称" prop="templateName"><el-input v-model="form.templateName" placeholder="请输入模板名称" /></el-form-item><el-col :span="24"><el-form-item label="阶段奖励类型" prop="stageType"><el-radio-group v-model="form.stageType" @change="handleChange"><el-radiov-for="dict in stage_type":key="dict.value":label="dict.value">{{ dict.label }}</el-radio></el-radio-group></el-form-item></el-col><div class="con"><div class="con-item" v-if="current == 0"><div class="input-items"><label for="name">达标交易量：</label><inputtype="text"placeholder="输入交易量"/></div></div><div class="con-item" v-if="current == 1"><div class="input-items"><label for="name">开通后（天）：</label><inputtype="text"placeholder="输入天数"/></div></div></div><!-- <el-form-item label="备注" prop="remark"><el-input v-model="form.remark" type="textarea" placeholder="请输入内容" /></el-form-item> --></el-form><template #footer><div class="dialog-footer"><el-button type="primary" @click="submitForm">确 定</el-button><el-button @click="cancel">取 消</el-button></div></template></el-dialog><script setup name="Rewards">const current = ref(0);const handleChange = (val) => {current.value = val;}</script>