Cavitation occurrence in the liquid film affects the lubrication performance of mechanical seals. A mathematical model of spiral groove liquid film seal was established based on the mass-conserving JFO cavitation boundary condition. The Reynolds governing equation was solved by the streamline upwind finite element method

and cavitation distribution was obtained. The calculation result was verified by cavitation visualization experiment. The influence of spiral groove geometrical parameters on cavitation characteristics were analyzed with the critical speed and critical pressure of cavitation as the characterization. The results indicate that the cavitation area in spiral groove is of wing section type

and it increases with increasing rotating speed and decreases with increasing inner pressure. The maximum circumferential length of cavitation is located near the groove radius. The critical speed of cavitation increases with the increase of groove number and depth

but decreases with the increase of spiral angle

radial seal dam extent and groove width ratio. The changing trends of critical pressure of cavitation with geometrical parameters are opposite to those of critical speed of cavitations. The effective control of cavitation can be achieved by reasonable selection of geometrical parameters.