Abstract: Aim at the problem of internal parameters variation and external load disturbance affecting the high-performance motor control,a fractional order integral sliding mode control（FOISMC）strategy is developed for PMSM drive system with fractional order sliding mode observer（FOSMO）. Based on FOISMC technology,a fractional order integral sliding mode speed regulator based on the new reaching law is designed.And a global integral sliding mode surface design method is presented,which can guarantee the global robustness of the system. Combining fractional order theory and sliding mode control theory,the FOSMO is constructed to achieve high accuracy estimation of the speed and rotor position. Simulation resulas validate the feasibility and effectiveness of the proposed scheme.