1.先在镜像站找到需要镜像,本例为ubuntu/xenial64,版本号最新的为:v20190215.0.0
2.获取最新的下载地址,出现下载地址后,使用curl+c停止
$ vagrant box add ubuntu/xenial64
==> box: Loading metadata for box 'ubuntu/xenial64'
box: URL: https://vagrantcloud.com/ubuntu/xenial64
==> box: Adding box 'ubuntu/xenial64' (v20190215.0.0) for provider: virtualbox
box: Downloading: https://vagrantcloud.com/ubuntu/boxes/xenial64/versions/20190215.0.0/providers/virtualbox.box
box: Download redirec