SOURCE

const Main = {
    data() {
        return {
            treeData: [{
                title: '1',
                key: '1',
                class: 'red-color',
                children: [
                    {
                        title: '1-1',
                        key: '1-1',
                        class: 'red-color',
                    },
                    {
                        title: '1-2',
                        key: '1-2'
                    }
                ]
            }],
            onLoadData: []
        };
    },
    beforeCreate() {

    },
    methods: {
        handleSelect(e) {

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

<script src="https://cdn.jsdelivr.net/npm/vue">

</script>
<script src="https://cdn.jsdelivr.net/npm/ant-design-vue/dist/antd.min.js">

</script>
<!-- 使用 cdn 引用方式需要注意是否锁定版本，默认指向最新版本 -->
<div id="app">
	<template>
		<a-directory-tree :show-icon="false" :tree-data="treeData" :load-data="onLoadData" @select="handleSelect" :defaultExpandedKeys="['Sys']">
		</a-directory-tree>
	</template>
</div>

@import url("https://cdn.jsdelivr.net/npm/ant-design-vue/dist/antd.min.css");
.red-color {
    color: red
}

.red-color > .ant-tree-node-content-wrapper {
    color: red !important;
}