In the switched reluctance motor speed control system, PI controllers often exhibit problems of poor dynamic performance, low control accuracy and large torque ripple. The PID controller can effectively improve the control performance, but because the PID controller has a differential link, a large system noise is likely to cause oscillation, resulting in unstable operation of the motor. To solve this problem, a parameter optimal fractionalorder PIDμ controller is designed based on conventional PI controller. The speed response of the system is selected to construct the target optimization function, and the gray wolf optimization algorithm is used to adjust the controller parameters to obtain the optimal parameters. The double loop model of SRM speed control system is established, the fractionalorder PIDμ controller is adopted in the speed loop and a compound current controller and PWM controller are adopted in current loop. The performance of conventional PI controllers and fractionalorder PIDμ controllers is compared in the case of sudden changes in speed and load transients. Simulation experiments show that the fractionalorder PIDμ controller retains the advantages of simple structure and convenient design of the PI controller. At the same time, it exhibits faster response speed and control precision, and has a good inhibitory effect on SRM torque ripple.