In view of the valve seat sealing structure of pneumatic flow valve,the two-dimensional axisymmetric model was established with the finite element software ANSYS,and the medium pressure load of valve seat sealing structure was simulated with the loading mode of Fluid Pressure-Penetration.The influence of different sealing parameters including medium pressure,preloaded spring force and valve seat structure parameters on its sealing characteristics was studied.The results show that the spring force is positively correlated with the maximum effective sealing pressure and maximum effective strain of the medium-free pressure.The outer diameter of the sealing surface and inclination angle of the sealing surface are negatively correlated with the maximum effective sealing pressure and maximum effective strain of the medium-free pressure.The inner diameter of the cover does not affect the maximum effective sealing pressure.The critical sealing parameters were optimized using the method of orthogonal experiment.After optimization,the maximum effective sealing medium pressure is increased by 14.14%,improving the sealing performance of the valve seat sealing structure.While the maximum equivalent strain is only increased by 1.87%,which has little impact on the sealing structure life.