The deformation and stress distribution characteristics of Yshaped rubber seal ring of an autoclave were analyzed by using finite element method (FEM),under the conditions of preinstallation,precompression and working state.The results show that the sealing of the sealing groove and cavity of the autoclave is mainly depended on the lip tip of the Yring,which is also the most vulnerable part.The relation of changes between the structural parameters and the stress of Yring was analyzed,and the structural parameters that had larger impact on the sealing performance of the Yring were obtained.Morevover,structure optimization of Yring was carried out by orthogonal test method.The results show that through optimization the Vonmises stress is reduced under the condition of ensuring the safe contact pressure of the contact surface,and the location of the maximum Vonmises stress is transfered from the original tip of the sealing lip to the inner side of the sealing lip,which effectively reduces the possibility of damage to the sealing lip tip.The increase in the angle of the lip and the decrease in the length of the Yring can save the material quantity.Therefore,the optimization of the Yring can reach the purpose of prolonging the service life and saving the material quantity.