The twodimension axisymmetric model of spring energized seal ring for liquid swivel of single point mooring system was established to analyze the compensation ability of Ushaped spring to system seal performance.Based on the orthogonal test method,the different sizes of spring energized seal ring were simulated to analyze the influence of each parameter on the contact pressure in the sealing area.Taking peak contact stress and linear contact pressure as the evaluation indexes of sealing performance,and the lip diameter,lip length,lip thickness and the thickness of pressed ring as the main parameters,the influence of various structural parameters on sealing performance was analyzed,and the optimal model size parameters were obtained.The results show that the embedded energy storage spring can significantly increase the contact pressure of the sealing ring and make the sealing performance better.With the increase of lip diameter and lip thickness,the peak contact pressure and line contact pressure are first increased and then decreased.With the increase of lip length,the peak contact pressure and line contact pressure are first slowly increased and then rapidly increased.Lip thickness has the greatest influence on peak contact pressure,followed by lip diameter,lip length and the thickness of pressed ring,while lip length has the greatest influence on line contact pressure,followed by lip diameter,lip thickness and the thickness of pressed ring.