To download 1688 live videos to your local computer, you can follow the steps below:

Use your mobile phone or other device to watch 1688 live videos.

On the video playback page, find the download button and click it.

Select the video quality and click the start download button.

You can also long press the video screen on the video playback page and select the "Save Video" option to save the video to your local computer.

Please note that some live videos may have download restrictions, and you may need to obtain the host's permission before you can download them. In addition, downloading videos requires a certain amount of network bandwidth and storage space, so please make sure your device has enough resources.