The invention provides a power control device and a control method thereof, and a surgery operating system. The device comprises a shell, a driving shaft, a transmission shaft, a driving gear, a transmission gear, an elastic device and a control pin; the driving shaft, which is driven by a power system, can do a rotating motion; the driving gear, which is driven by the driving shaft, can do a rotating motion; under the action of external force, the elastic device can be transformed from a basic state to a target state by virtue of the control pin; the elastic device is arranged in the shell and is connected to the transmission shaft, and when the elastic device is under the target state, the driving gear and the transmission gear are controlled to get separated; when the elastic device is under the basic state, the driving gear and the transmission gear are controlled to get meshed; when the transmission gear and the driving gear are meshed, the transmission shaft, which is driven by the driving gear, can do a rotating motion; and a first end of the transmission shaft is connected to an external surgical blade, and the external surgical blade, which is driven by the transmission gear, can do a rotating motion. With the application of the technical scheme provided by the invention, the motion state of the surgical blade is controlled.