Taking the sealing contact strength as the index and considering the effect of effective contact length on the sealing characteristics,the sealing characteristics of VX gasket for a subsea wellhead connector under different preload,working pressures and structure parameters were analyzed by using finite element method,and compared with the analysis results of sealing characteristics with single sealing surface contact stress as evaluation index.The results indicate that preload is an important factor affecting the sealing performance,the preload should be larger to ensure the safety of the locking structure.Compared with the contact stress, the sealing contact strength can better simulate the trend of sealing performance of VX gasket changing with the preload, working pressure and structure parameters.Therefore,the sealing contact strength should be selected as the index to assess the VX gasket sealing performance.