Permanent magnet synchronous motor (PMSM) control system has important applications in civil and military fields such as robot, radar control and photoelectric turntable. GD32F450, as a domestic high-performance processor, has a wealth of motor control peripherals. It is very suitable for motor control system under the background of independent and controllable chip in China. A servo drive circuit is designed for a low-voltage PMSM. In view of the common PI speed controller prone to overshoot, the sliding mode speed controller is used instead. Compared with the PI control, the speed control can be smoother. The test structure proves the rationality of the scheme.