后续发现应该是vuecli版本的问题，在router文件夹里的index.js中使用createRouter和createWebHistory

import { createRouter, createWebHistory } from 'vue-router'
import Home from '../components/Home'
import Course from '../components/Course'
const routerHistory = createWebHistory()
const routes=[
 //这里和vue2一样
    {
        path: '/home',
        component: Home,
    },
    {
        path: '/course',
        component: Course,
    }
]
const router = createRouter({
    history: routerHistory,
 routes
})
 
export default router

并在main.js中

import { createApp } from 'vue'
import App from './App.vue'
import router from './router/index'

const app = createApp(App)
app.use(router).mount('#app')