SOURCE

new Vue({
    el: '#app',
    data: {
        list: [
            {
                name:123123123
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }, {
                name:1
            }
        ]
    }
})

<div id="app" class="box">
    <ul class="list">
        <li v-for="item in list">{{item.name}}</li>
    </ul>
</div>

.box {
    display: flex;
    border: 1px solid red;
    height: 100px;
}
.list {
    display: flex;
    flex-direction: column;
    flex-wrap: wrap;
    width: 100%;
}
li {
    list-style: none;
    min-width: 50%;
}