A metal sealing element structure was designed by using NiTi alloy material,and the numerical model of the sealing element and its components was established.The maximum stress,the setting force and the contact stress were proposed to evaluate the sealing performance of sealing elements.The influence of structural parameters on the sealing performance was analyzed.The results show that the maximum stress is increased monotonously with the increasing of expansion ring radius and arch radius,and increased at first then decreased with the increasing of support ring width,arch thickness and unloading groove radius.The setting force is increased monotonically with the increasing of support ring width,expansion ring radius,arch radius and arch thickness, and decreased monotonically with the increasing of unloading groove radius.The contact stress is increased nonlinearly with the increasing of support ring width,expansion ring radius and arch thickness,and decreased nonlinearly with the increasing of arch radius and unloading groove radius.Arch radius and arch thickness have a significant effect on the sealing performance of the sealing elements,and the sealing performance can be improved by reducing arch radius or increasing arch thickness.