有一种笨办法，就是用AUDACITY录下你听到的声音

1. Open Audacity, and in the dropdown menu under "Audio Host," choose "Windows WASAPI."

2. In the recording device drop-down, choose your computer's default speakers or headphones. Depending on your setup, you might also need to pick the option labeled "Loopback." This will differ depending on what sort of sound card your PC has.

这个方法万能，听见就能录下，就是花时间。

或用下载工具：

实用电脑： 这个是开源免费无广告的youtube下载工具 - 由hot_powerz发表 - 文学城 (wenxuecity.com)