For the sealing structure at the spool of the hydraulic valve,the design idea of the combined sealing structure was adopted,and the pre-tightening force and compensation force were provided by the compression wave spring.A numerical model of the sealing structure was established,and the contact stress and rotational friction torque of the dynamic sealing surface of the hydraulic valve were analyzed.According to different influencing factors,the contact stress distribution between the dynamic sealing surfaces and the change of the peak contact stress were simulated.And by applying fluid pressure,the influence of each factor on the rotational friction torque of the hydraulic valve was studied.Orthogonal experiments were designed and intuitive analysis and variance analysis were carried out to determine the optimal sealing structure parameters.The results show that after optimization,the contact stress between the main seal pair increases and the rotational friction torque decreases,which effectively improves the sealing performance of the main seal structure.