The cylinder cushion is located between the cylinder head and the cylinder block, also known as the cylinder bed. Its function is to fill the microscopic pores between the cylinder block and the cylinder head to ensure good sealing at the joint surface, and then to ensure that the seal of the combustion chamber prevents cylinder leakage and water jacket water leakage. With the continuous strengthening of the internal combustion engine, the thermal load and mechanical load are increasing, and the sealing of the cylinder gasket is becoming more and more important. The requirements for structure and materials are: sufficient strength and heat resistance under high temperature, high pressure and high corrosion gas conditions; A lot of damage or deterioration, corrosion resistance; It has certain elasticity and can compensate the unevenness of the joint surface to ensure sealing; Long service life.