Clock calibration method and system

The invention discloses a clock calibration method, which comprises the following steps of: receiving a start-of-frame (SOF) signal of a universal serial bus (USB) host of any personal computer (PC) as a reference clock signal; starting to count synchronously with the received SOF signal, and setting a numerical value of a counting time interval to be the same as that of a time interval of the SOF signal; performing comparison and calculation to obtain a difference value between the actual counting time interval and the time interval of the SOF value; and calibrating a clock according to the difference value. The invention also discloses a clock calibration method-based clock calibration system. An accurate clock of the PC is taken as a reference clock, and any PC is connected to achieve a clock calibration effect; and a user can introduce the SOF signal of the USB host of the PC through a signal detection unit to automatically fulfill the aim of clock calibration, so that a convenient and quick calibration way is provided for clock calibration, and convenience is brought to the user.