<el-input placeholder="请输入搜索内容" v-model="params.search">

const delay = (function () {
  let timer = 0
  return function (callback, ms) {
    clearTimeout(timer)
    timer = setTimeout(callback, ms)
  }
})();

data() {
  return {
    params: {
      page: '1',
      search: ''
    }
  }
},

watch: {
  "params.search"() {
    delay(() => {
    this.fetchData();
    }, 1000);
  }
}