High-precision permanent magnet synchronous motors have extremely high requirements on the dynamic performance and speed stability of the speed control system. Aiming at the problems of poor dynamic performance of traditional motor control methods and large interference from uncertain loads, a speed-current non-cascaded direct speed controller was designed using the method of model prediction, which replaced the traditional proportional-integral (PI) regulator. Eliminate the double-ring cascade structure. The prediction model performs long-distance prediction on the speed, and uses a more restrictive cost function to optimize the dynamic and static performance of the control system. Finally, the simulation experiment shows that compared with the traditional PI vector control, the speed overshoot is reduced to zero, the maximum speed drop is reduced by 45r/min when the load is suddenly applied, and the recovery time is accelerated by 0.055s, at the same time, the effect of suppressing the fluctuation of speed and current is significant, and the system dynamic performance and anti-interference ability are better.