Air filter is a type of filter, also known as air filter cartridge or air filter style. It is mainly used for air filtration in engineering locomotives, automobiles, agricultural locomotives, laboratories, sterile operating rooms, and various precision operating environments.

During engine operation, large amounts of air are required. If air is unfiltered, suspended dust accelerates the wear of the piston group and cylinder. Large particles can cause serious "cylinder pulling," especially in dry and sandy environments. The air filter ensures clean air enters the intake system, protecting engine longevity.