In order to meet the needs of high precision drive control system in the field of ultraprecision machining, AC permanent magnet torque motor is developing towards high torque and low ripple, and there is still a big gap between domestic and foreign research. Therefore, according to the actual engineering needs, the structure of large torque, low pulsating AC permanent magnet torque motor was analyzed, and the motor based on the technical requirements was optimized. Finally, the method of finite element analysis was used to analyze the proposed AC permanent magnet torque motor, and verified the design of the motor overload capacity, the performance of cogging torque and the suppression of the ripple torque. The simulation results showed that the designed motor had excellent performance.