SOURCE

var Main = {
    data() {
        return {
            start: "2018-5-4",
            end: "2018-5-25",
            value1: '',
            value2: '',
            pickerOptions1: {
                disabledDate(time) {}
            }
        }
    },

    watch: {
        value1(time) {
            console.log(time);
            this.test();
        },
        value2(time) {
            console.log(time);
            this.test();
        }
    },

    methods: {
        test() {

            this.pickerOptions1.disabledDate = time => {
                let start = this.value1 ? new Date(this.value1).getTime() : new Date(this.start).getTime();
                let end = this.value2 ? new Date(this.value2).getTime() : new Date(this.end).getTime();
                return time.getTime() < start || time.getTime() > end;
            }
        }

    },
    created() {
        this.test();
    }
};
var Ctor = Vue.extend(Main);
new Ctor().$mount('#app');

<script src="//unpkg.com/vue/dist/vue.js">
</script>
<script src="//unpkg.com/element-ui@2.3.8/lib/index.js">
</script>
<div id="app">
    <template>
        <div class="block">
            <span class="demonstration">
                开始
            </span>
            <el-date-picker v-model="value1" align="right" type="date" placeholder="选择日期">
            </el-date-picker>
        </div>
        <div class="block">
            <span class="demonstration">
                结束
            </span>
            <el-date-picker v-model="value2" align="right" type="date" placeholder="选择日期"
            :picker-options="pickerOptions1">
            </el-date-picker>
        </div>
    </template>
</div>

@import url("//unpkg.com/element-ui@2.3.8/lib/theme-chalk/index.css");