Provided is a control system and method for a power-driven nail gun, which includes a battery, a motor, a flywheel rotating along with the motor, an impacting member receiving kinetic energy of the flywheel and a nail channel providing a channel for a nail to move along therewith when hit by the impacting member. The method includes utilizing a microcontroller to provide a pulse width modulation (PWM) signal for a driving circuit to drive the motor based on the PWM signal; and in response to reaching a target rotation speed by the motor, utilizing the microcontroller to output a corresponding PWM duty to the driving circuit based on the voltage of the battery, to make the motor maintain at the target rotation speed. The nails obtain stable and consistent kinetic energy and stability of nail firing is effectively improved.