Abstract: Tractor is an important means of production and plays an important role in the national economy.The contact area between tire and ground will directly affect the driving force of tractor, and then affect the working efficiency and fuel consumption of tractor.The automatic tire charging and releasing system can adjust the tire pressure timely according to the working conditions, and realize the purpose of reducing the tractor fuel consumption and improving the working efficiency by dynamically changing the tire contact area with the ground.Based on the experimental data of tire pressure and tractor fuel consumption, and taking the typical automatic tire charging and releasing system of tractor in the world as an example, this paper expounds the working principle and realization mode of automatic tire charging and releasing system, and summarizes the future development trend, which can be used for reference by tractor designers and developers in China.