In view of the combination seal form of Glyd ring used in the piston of servo hydraulic cylinder,the twodimensional axisymmetric finite element model of Glyd ring was established.By using the finite element analysis software ANSYS Workbench,the influences of different sealing parameters (precompression rate of Oring,thickness of rectangular slip ring and material hardness of Oring) on the dynamic sealing performance of Glyd ring were studied.The results show that in the middle region of the rectangular slip ring,the maximum contact pressure on the main sealing surface is increased with the increase of Oring precompression rate and Oring material hardness,but decreased with the increase of the thickness of the rectangular slip ring.The starting friction is increased with the increase of the precompression rate of the Oring and the hardness of the Oring material,but decreased with the increase of the thickness of the rectangular slip ring.Based on the response surface method,the maximum contact pressure and the minimum starting friction force were taken as the optimization objectives to optimize the Glyd ring sealing parameters,and the optimal design was obtained to achieve the optimization objectives.After optimization,the maximum contact pressure is increased,the starting friction is decreased,and the sealing performance of Glyd ring is improved.