参考官方文档：点击跳转

具体实现：

wxml：

<button class="avatarBtn" open-type="chooseAvatar" @chooseavatar="onChooseAvatar">
    <image class="avatar" :src="avatarUrl"></image>
</button>

js:

const defaultAvatarUrl =
'https://mmbiz.qpic.cn/mmbiz/icTdbqWNOwNRna42FI242Lcia07jQodd2FJGIYQfG0LAJGFxM4FbnQP6yfMxBgJ0F3YRqJCJ1aPAK2dQagdusBZg/0'
const avatarUrl = ref(defaultAvatarUrl)
//图片路径容器
const imgInfo = reactive({
		imgs: ''
	})

// 头像上传事件
	const onChooseAvatar = (e) => {
		console.log(e);
		avatarUrl.value = e.detail.avatarUrl;
		console.log(e.detail.avatarUrl);
		uni.uploadFile({
			url: 'https://xxxx', //仅为示例，非真实的接口地址
			filePath: e.detail.avatarUrl,
			name: 'file',
			formData: {
				'user': 'test'
			},
			success: function(res) {
                   //剥离接口返回路径
				imgInfo.imgs = JSON.parse(res.data)
				console.log(imgInfo.imgs.data.url);
			}
		});
	}

之后根据注册需求适当调整即可  (〃￣︶￣)人(￣︶￣〃)