As we all know, the starting of the engine needs the support of external force, and the car starter is playing this role. Generally speaking, the starter uses three components to implement the entire start-up process. The DC series motor introduces the current from the battery and causes the drive gear of the starter to produce mechanical motion; the transmission mechanism meshes the drive gear into the flywheel ring gear, and can be automatically disengaged after the engine is started; the starter circuit is switched on and off by a electromagnetic switch to control. Among them, the motor is the main component inside the starter, and its working principle is the energy conversion process based on Ampere’s law that we encountered in junior high school physics, that is, the action of the current-carrying conductor in the magnetic field. The motor includes the necessary armatures, commutators, magnetic poles, brushes, bearings and housings. Before the engine can run on its own power, it must be rotated by external force. The process in which the engine transitions from a static state to a self-running state with the help of external force is called engine starting. There are three types of engine starting methods: manual starting, auxiliary gasoline engine starting and electric starting. The manual starting method adopts rope pulling or hand cranking, which is simple but inconvenient and labor-intensive. It is only suitable for some low-power engines, and is only reserved as a backup method in some cars; auxiliary gasoline engine starting is mainly used in high-power engines. On the diesel engine; the electric starting method is easy to operate, quick to start, has the ability to start repeatedly, and can be controlled from a long distance, so it is widely used in modern cars.