The contact pressure and friction on the contact surface of Y sealing ring between the piston and piston rod were analyzed by using finite element analysis software ABAQUS.Aimed at the large contact pressure and the volatile friction between the contact surface of the Y sealing ring,an O ring was added on the lip of the original Y sealing ring,which can provide static seal and elastic support for the Y sealing ring.The results show that the contact stress and friction of the optimized Y sealing ring are decreases obviously,and the friction curve becomes more stable.This new structure has good sealing effect,and also reduce the wear failure of the Y sealing ring caused by too much friction,as a result,the service life of the Y sealing ring is prolonged.