Based on the cavitation model meeting massconserving,a threedimensional model of spiral groove liquid film seal was established by CFD FLUENT software.The effects of spiral groove structure parameters on the occurrence of cavitation were discussed,and the effects of cavitation on the opening force,the stiffness of liquid,pumping flow rate and so on were analyzed.The results indicate that,by the gasphase volume fraction changes in the liquid film as the criterion,the cavitation effect is increased as the groove depth and number increase,and is increased first and then decreased as the groove diameter width diameter ratio increases,but becomes weaken as the spiral angle increases.Compared with those calculated under no consideration of cavitation effect,the values of liquid film opening force and pumping flow rate are ever reduced but the variation tendencies almost remain uniform,while the liquid film stiffness fluctuates greater within a certain range of spiral groove structure parameters and affects the liquid film stability,so cavitation easily leads the instability of seals.