AS far as the traditional Direct Torque Control (DTC) of PMSM be concerned, it has some disadvantages, such as speed fluctuation, large torque ripple, inconstant switch frequency, etc. By analyzing and researching the control algorithm of Pan-Boolean algebra, this paper believed that the Pan-Boolean algebra PID control can replace the traditional rotative speed regulator; And aiming at the disadvantage of the inconstant switch frequency, this paper argues that the original look-up table module can be substituted in SVPWM module. In addition, an improved scheme of Direct Torque Control method of PMSM is presented in this thesis. The results of the corresponding simulation model built in MATLAB/Simulink show that the system can effectively reduce the torque ripple and improve the system stability of rotation speed, and has a better dynamic response ability.