Based on initial 2-D axisymmetric finite element model of spring energized seal ring,the process of ring’s assembly and being loaded was simulated,and several physical quantities that represent the performance of seal ring,such as contact pressure distribution,contact width and the maximum contact pressure were achieved.Further attention was focused on failure model of PTFE for setting up the standards of sealing characteristics.Following the standards,those physical quantities under variable conditions were analyzed.The model was applied to the design of sealing system,and the influence of compression rate on sealing characteristics was analyzed.The results show that the maximum pressure of the contact area,which is increased along with the medium pressure,is always higher than the medium pressure,indicating this kind of seal can keep its sealing characteristic when loaded the medium pressure.The contact width as well as the line-contact pressure is also increased along with the higher medium pressure.