Automotive engine is a very precise part, very small impurities will damage the engine. Therefore, before entering the cylinder, air must pass through the fine filtration of the air filter before entering the cylinder. Air filter is the guardian God of the engine. The condition of air filter is related to the life of the engine. If dirty air filters are used in automobiles, insufficient air intake and incomplete fuel combustion will result in unstable engine operation, power decline and increased fuel consumption. Therefore, the car must keep the air filter clean.