Yes, you can tether multiple cameras to one computer, but true simultaneous triggering over USB is generally not reliable. Based on the answers, Canon SDK-based control is typically limited to one camera connection at a time, or requires handling each camera separately, which introduces delay.

Tools such as digiCamControl can control multiple cameras from one PC, and the CameraControl.Devices package may help if you're building this in C#. However, USB triggering across multiple cameras will usually have noticeable lag between bodies—roughly a few hundred milliseconds rather than perfect sync.

If your needs are simple, gPhoto2 may also work for basic capture-and-download tasks. More advanced custom control would require low-level USB communication rather than relying on the Canon SDK.

If you need near-simultaneous capture, the practical solution is usually separate triggering hardware rather than USB-only control. Running separate virtual machines/OS instances per camera is another possible workaround, but it is resource-heavy and not ideal.