The surface permanent magnet synchronous motor (SPMSM) drive system has been widely used in the industry due to its high-power density, high efficiency, and easy to control. In this paper, a frequency-adaptive periodic controller, which self-tunes the model in real time to match the external signal closely, is proposed for a speed-loop controller of a fault-tolerant SPMSM drive system, including normal operating conditions and faulty operating conditions. The faulty conditions consist of an IGBT open-circuit and an IGBT short-circuit. A digital signal processor, TMS-320F-2808, manufactured by Texas Instruments, is used as a control center to execute the proposed fault-detection, fault diagnosis, and frequency-adaptive periodic control algorithms. Experimental results show the proposed frequency-adaptive periodic controller can provide better performance than the PI controller and the classic periodic controller, including transient responses, load disturbance responses, and tracking responses under normal conditions and faulty conditions.