With the expansion of the application field of dynamic pressure non-contact mechanical seal and the complexity of its operating conditions,the liquid film phase transition has become one of the key factors affecting its working stability and reliability.The generation mechanism of vaporization and cavitation was compared and analyzed for the two phase transition types of end surface liquid film vaporization and liquid film cavitation.Several common types of phase change models were introduced,such as Thermal Lattice Boltzmann model,Zwart-Gerber-Belanri model and so on.The research progress on the influence of the structural parameters and operating parameters of the end groove on the liquid film phase transition was reviewed.In terms of the research on the influence of phase change,it was proposed that the current research mainly focused on the influence of a single factor in the groove structure parameter or working condition parameter,but the research on the comprehensive influence of multiple factors was still relatively simple.The possible development direction of liquid film phase transition is pointed out,such as the innovation of the theoretical calculation model of the comprehensive effect of vaporization and cavitation,the correlation between the phase change of the liquid film and the stability of the seal under extreme conditions,the breakthrough of the phase change monitoring technology.