您可以阅读/sys/bus/usb/devices/usb?/speed-它会为您提供根集线器的总线速度(以Mbps为单位):1.5、12、480或5000 .前两个表示USB1(低速或全速)，第三个USB2和第四个USB3.

You can read /sys/bus/usb/devices/usb?/speed - it'll give you the bus speed of the root hub(s) in Mbps: either 1.5, 12, 480 or 5000. The first two indicate USB1 (low speed or full speed), the third USB2 and the fourth USB3.