Piston rings are used for sealing, oil control, heat conduction and guidance. The piston ring is a metal ring embedded in the piston groove. Piston rings are divided into two types, namely compression rings and oil rings. The compression ring can be used to seal the combustible mixture in the combustion chamber; The oil ring is used to scrape off the excess oil on the cylinder. Piston rings are widely used in various power machines, such as steam engines, diesel engines, gasoline engines, compressors and hydraulic presses. Widely used in cars, trains, ships, yachts and so on. Piston ring is the core component of fuel engine, which seals the gas together with cylinder, piston and cylinder wall.