Background there is a problem in the introduction of Axios
code

import Vue from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'
import axios from 'axios'


import ElementUI from 'element-ui';
import 'element-ui/lib/theme-chalk/index.css';
import './reset.css'

Vue.config.productionTip = false
Vue.use(ElementUI);
axios.default.baseURL = 'https://www.fastmock.site/mock/ad1bc58516abb5f0f452402035be2443/houtai'
Vue.prototype.$http = axios

This is because the order of the two lines of code is wrong
change to

import Vue from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'
import axios from 'axios'
import ElementUI from 'element-ui';
import 'element-ui/lib/theme-chalk/index.css';
import './reset.css'
axios.default.baseURL = 'https://www.fastmock.site/mock/ad1bc58516abb5f0f452402035be2443/houtai'
Vue.prototype.$http = axios
Vue.config.productionTip = false
Vue.use(ElementUI);