In order to improve the sealing performance of bud-shaped seal,considering the permeability effect of medium pressure,the sealing characteristics of bud-shaped seal under the action of medium pressure and the influence of motion speed,friction coefficient and geometric parameters on the dynamic sealing performance of the bud-shaped seal were studied by using the finite element analysis software ANSYS.The results show that the contact pressure on the sealing surface of bud-shaped seal is mainly borne by the support part under the action of medium pressure,and the sealing ring will not be squeezed into the sealing gap,which has good anti-wear and anti-extrusion properties.Under dynamic sealing conditions,the contact pressure generated by external stroke is greater than that generated by internal stroke.The contact pressure of external stroke increases with the increase of friction coefficient,while the contact pressure of internal stroke is opposite.The motion speed has little influence on the performance of dynamic sealing.The response surface optimization was carried out according to the influence of geometric parameters on sealing performance,and the maximum equivalent stress on the piston rod surface was reduced on the premise of meeting the sealing requirements,and the risk of sealing failure of the piston rod due to surface fatigue wear was reduced.