The main function of the automobile gearbox is to adjust the driving force and speed of the car in real time to adapt to the actual road conditions faced by the car in the process of use, such as rapid stop, low speed or high speed, acceleration, deceleration, climbing and reversing. Compared to the manual transmission, the core of the automatic transmission is to achieve automatic shifting. The so-called automatic shift means that in the process of driving, the driver controls the accelerator pedal according to the needs of the driving process, and the automatic transmission can automatically change into different gear according to the engine load and the operating conditions of the car. Based on the actual needs of automobile maintenance positions, the course introduces the structure, principle, disassembly, maintenance, detection and fault diagnosis knowledge and operation of automobile automatic transmission. This course includes the following learning items: the general understanding of automatic transmission, the understanding and disassembly of automatic transmission, the understanding and disassembly of hydraulic torque converter, the routine inspection and testing of automatic transmission, the overhaul of the main components of automatic transmission, etc.