In order to improve the angular speed control accuracy of permanent magnet synchronous motor（PMSM）, a thirdorder feedback controller was designed. The structure characteristics of the PMSM and the loop characteristics of the magnetic field were analyzed. The motion model of the PMSM was obtained by using its angular velocity. The state equation of the rotor with symmetrical winding was obtained by using stator inductance and resistance. The angle position of the motor was introduced into the state equation, and the full order mathematical model of the PMSM was obtained. Based on the full order mathematical model, the third order model of the angle position of the PMSM was calculated. A thirdorder feedback controller was constructed, and the input voltage of the motor was obtained through the target angle position to control the angular velocity. The sliding mode observer and the designed method were used to track the target angular position and speed. The results show that the tracking effect of the proposed method is better than that of the sliding mode observer, and the target angular position and speed can be tracked more accurately, and the angular speed of the PMSM can be controlled accurately.