问题截图

import zhCn from "element-plus/es/locale/lang/zh-cn";
或者
import zhCn from "element-plus/lib/locale/lang/zh-cn";

const locale=zhCn
     <el-config-provider :locale="locale">
    <el-date-picker v-model="value1" type="datetimerange" range-separator="至" start-placeholder="开始时间"
       end-placeholder="结束时间" value-format="YYYY-MM-DD HH:mm:ss" @change="settime" />
       </el-config-provider>

完美解决