As electronic technology is widely used in automobiles, small motors will be more widely used in automobiles, and the number of motor applications will increase as well. As the small motor and actuating element of the automobile electrical equipment, the usage increases rapidly every year, and the automobile has become the application field of the small motor. With the growth of the demand for small motor vehicles, the motor technology is also improving. The car used for reasons of the rapid growth of demand for small motor has the following several aspects: 1, using a large number of new institutions, new equipment, auto parts, 2 power automation 3, some new system design with motor drive. The motor drive of the small motor is mainly distributed in the three parts of the automobile engine, chassis, body and accessories. First, the application of automotive engine components: mainly in the automotive starter, EFI control system, radiator and generator applications. These components shall have more than one DC motor and stepper motor. The two is the application of automobile chassis frame, mainly in the automotive electronic control suspension system, cruise control system and electric power steering device, vehicle stability control system, automobile cruise control system, explosion-proof braking system and the driving and driving force control system application. Among them, the permanent magnet DC motor or permanent magnet stepper motor is widely used. Three is the application of automotive body parts: mainly in the central door lock device, electric rearview mirror, automatic lifting antenna, automatic sunroof, automatic headlights, automatic seats and so on. The universal application of permanent magnet DC motor and permanent magnet stepper motor. With the motor technology is widely used in automobile, small motor used in the car will be more broad, such as information systems, navigation systems, car audio and video entertainment systems, mobile communication system, the number of motor applications also increased. In addition, for electric vehicle hybrid vehicles, power systems are required to use motors.