Based on the mathematical model of brushless DC motor, a simulation model of brushless DC motor (BLDCM) double closed-loop control system is established by using the voltage equation, the electromagnetic torque equation and the motion equation based on Matlab, then introduces the sub-modules of the controlling system in detail. PID control is used in the speed loop and hysteresis current track of PWM is used in the current loop. The reasonability and validity are testified by the simulation results and this novel method offers a new thought way for designing and debugging actual motors.