npm install mermaid

<template>
  <div class="container">
    <pre class="mermaid">
      graph LR
        A[立项] --> B[需求分析]
        B --> C[设计]
        C --> D[开发]
        D --> E[测试]
        E--> F[发布]
        F --> G[维护]
    </pre>
  </div>
</template>
<script>
import mermaid from "mermaid"; //引用mermaid
export default {
  mounted() {
    mermaid.initialize({ startOnLoad: true });
    mermaid.init();
  },
}
</script>

教程 | Mermaid 中文网 (nodejs.cn)