Based on orthogonal array method,the twodimensional axial symmetric geometric model of a Xring with backup ring structure used in hydraulic servo system under high pressure was created by using the ANSYS software,and the influence of groove structure,backup ring structure,installation status and operating conditions on the static sealing performance and reliability of sealing ring were analyzed.The structure of Xring was optimized based on the optimization objective to minimize the maximum value of Von Mises stress of the sealing ring.The results indicate that too small or too large groove notch and bottom chamfer sizes will all cause concentrated stress of Xring.The maximum Von Mises stress is increased first and then deceased along with the increasing of the chamfer and width of backup ring,and is increased rapidly with the increasing of sealing clearance.Increasing the compression ratio of Xring is helpful to improve the contact pressure on the sealing surface,while the maximum Von Mises stress will also increase.Increasing the tensile ratio of Xring is helpful to reduce the Maximum Von Mises stress,but the installation of Xring becomes difficult.The parameters of operating conditions,installation status and backup ring structure are the major factors which affect the sealing performance and reliability of Xring in turn,under high pressure more than 10 MPa,which is the object of research on the optimization design of sealing ring structure.