The invention relates to a control method of a servo motor. The control method of the servo motor comprises the steps that when a servo driver receives a rotating speed instruction given by an upper motion controller, and the rotating speed instruction is not zero, the servo driver works in a rotating speed closed-loop control mode, receives the rotating speed instruction of the upper motion controller, and controls a controlled object to rapidly and stably arrive at a target position; when the rotating speed instruction is set to be zero, the servo driver works in a motor position closed-loop control mode, a result obtained through calculation of a position loop serves as an actual rotating speed instruction, and the controlled object can be fixed to the target position. Influence of rotating speed feedback value fluctuation on a control result is eliminated, and shakes of the controlled object are prevented.