Compression performance of spring energized seal is the key to evaluating the reliability of electro-hydraulic actuator.While as the elastic component of the spring energized seal,the compression stiffness and maximum elastic compression of U-spring are the main factors determining the energized performance.An elastic-plastic finite element model of U-spring was established based on the standard measured material parameters.The compression stiffness,maximum elastic compression and maximum linear compression of U-spring were obtained.The influence of typical structural parameters of U-spring on compression performance was analyzed,and a multi-factor mathematical model was constructed based on the response surface method.The accuracy of the calculation model was verified through multiple spring compression tests.The results show that spring thickness,total section length,slotting width,period width and bending radius are the main influencing factors of compression stiffness,and their effects decrease sequentially.Spring thickness,total section length,and root arc radius are the main influencing factors of maximum elastic compression,and their effects decrease sequentially.The repeated compression test shows that the plastic deformation caused by spring yield will accumulate with the number of compression cycles,leading to a decrease in the width of the spring opening and a decrease in the dynamic sealing performance of the sealing ring.When the energy storage sealing ring is used for dynamic sealing,its compression should not exceed the maximum elastic compression.