Abstract: In view of the complexity and control performance of PMSM control drive system for machine tools, which was easily affected by load disturbance and nonlinear disturbance, the advantages of additive decomposition theory were used to decompose PMSM drive control system into primary system and auxiliary system. Among them, the auxiliary system adopted the improved sliding mode control method, which not only ensured the stability and robustness of the system, but also effectively weakened the chattering characteristic of the traditional speed sliding mode controller. The main system adopted the tracking strategy based on the current double closed loop, which could better control the response performance of the drive system and improve the engineering practicability of the method. The simulation results had shown that the structure control improved the dynamic performance and robustness of the system, and could be used in machine tool motor drive system.