A motor braking system of a stage light includes a controlled component, a braking motor that drives the controlled component to move, and a controller, wherein the braking motor includes a motor unit and a braking unit for braking the motor unit; the braking motor is a power-off locking motor; the motor unit and the braking unit are both electrically connected to the controller; and when detecting that the motor unit is powered on, the controller controls the motor unit to provide a holding torque, and controls the braking unit to be powered on to release a locked state.