The quality requirements of dimming motor for headlamp are introduced. The operation of this motor is very complicated and different from general industrial application. Therefore, the headlamp dimming motor requirements are also very high. This paper introduces the quality requirements of automobile headlamp dimming motor. The automobile headlamp dimming motor should have the characteristics of high power, strong overload capacity, good acceleration performance and long service life. In the constant torque region, a larger torque is needed at low speed to meet the requirements of starting and climbing, and in the constant power region, a higher speed is needed at low torque to meet the requirements of high speed driving on a flat road, automotive headlamp dimming motor should be able to achieve regenerative braking, energy recovery and battery feedback, so that the energy efficiency of electric vehicles to achieve the best, improve fuel efficiency, improve a charging range.First of all, the automobile headlamp dimming motor realizes electronic commutation by using semiconductor owned property switch device, that is, replacing traditional contact commutator and brush with electronic switch device. The utility model has the advantages of high reliability, no commutating spark, low mechanical noise and the like. Secondly, the head lamp dimming motor is an electric vehicle motor, which uses a magnetic position sensor installed on the stator assembly, an electric vehicle motor uses a photoelectric position sensor, the photoelectric sensor is installed on a certain position of the stator assembly, the rotor is provided with a shading plate and the light source is a light-emitting diode or a small light bulb. Finally, the electronic switch circuit controlled by the position sensor output provides the working voltage of the stator winding. When the rotor rotates, the photosensitive device on the stator will produce a certain frequency intermittent pulse signal due to the action of the shading plate. When the rotor rotation when the magnetic field changes, used to detect permanent magnets.