想要在地图上绘制自由图形，只需要在new Draw的时候多加一个配置项就行。

 function addInteraction() {const value = typeSelect.value;if (value !== "None") {draw = new Draw({source: source,type: typeSelect.value,freehand: true, //是否自由绘制});map.addInteraction(draw);}}

 完整代码：

<template><div class="box"><h1>Freehand Drawing</h1><div id="map"></div><form><label for="type">Geometry type &nbsp;</label><select id="type"><option value="LineString">LineString</option><option value="Polygon">Polygon</option><option value="Circle">Circle</option><option value="None">None</option></select></form></div>
</template><script>
import Draw from "ol/interaction/Draw.js";
import Map from "ol/Map.js";
import View from "ol/View.js";
import StadiaMaps from "ol/source/StadiaMaps.js";
import { OSM, Vector as VectorSource } from "ol/source.js";
import { Tile as TileLayer, Vector as VectorLayer } from "ol/layer.js";
var arc = require("arc");
export default {name: "",components: {},data() {return {map: null,extentData: "",};},computed: {},created() {},mounted() {const raster = new TileLayer({source: new StadiaMaps({layer: "outdoors",}),});const source = new VectorSource({ wrapX: false });const vector = new VectorLayer({source: source,});const map = new Map({layers: [raster, vector],target: "map",view: new View({center: [-11000000, 4600000],zoom: 4,}),});const typeSelect = document.getElementById("type");let draw; function addInteraction() {const value = typeSelect.value;if (value !== "None") {draw = new Draw({source: source,type: typeSelect.value,freehand: true,});map.addInteraction(draw);}}typeSelect.onchange = function () {map.removeInteraction(draw);addInteraction();};addInteraction();},methods: {},
};
</script><style lang="scss" scoped>
#map {width: 100%;height: 500px;
}
.box {height: 100%;
}
</style>