Under the condition of gas-liquid mixed transportation,the high gas content in the sealing cavity will cause the gas to enter the sealing liquid film,resulting in the “instability” phenomenon of the sealing ring.In order to explore the influence of gas-containing medium on the performance of mechanical seal,based on the Mixture multiphase flow model,the gas-liquid two-phase distribution in the end surface liquid film and sealing performance of mechanical seal were studied by establishing the spiral groove liquid film model on the end surface.The results show that the gas volume fraction in the liquid film increases with the decrease of the bubble diameter.The two-phase distribution law of the seal end face is similar under different inlet gas content,and there exists higher gas content appears at the groove root radius.With the increase of void fraction,rotation speed,and pressure difference,the pressure at the root of the groove increases,which affects the sealing performance.Under the same void fraction,rotation speed and pressure difference,with the increase of film thickness,the leakage increases and the opening force decreases,and the smaller film thickness is more sensitive to the change of working condition parameters.The groove depth has a stronger correlation with the film thickness,both effects should be considered comprehensively when optimizing the structure of mechanical seal.