Cavitation is an inevitable phenomenon in the high speed oil film lubrication bearing,which influences the oil film bearing capacity and stability of floating ring bearing.The influences of cavitation on the inner and outer oil film pressure distributionof floating ring bearing,and the gas holdup and oil supply pressure on the bearing capacity were analyzed by the mixture(Mixture)multiphase model in Fluent software.The results show that cavitation leads to the decrease of the oil film pressure’s peak value,and the influence to internal oil film is greater than the outer oil film.Cavitation will result in the decrease of bearing capacity of oil film,the greater the gas holdup,the lower the bearing capacity.The oil supply pressure has a certain effect on the bearing capacity at constant gas holdup.Analysis of oil film cavitation lays the foundation for the research on the leaning and instability of floating ring bearing.Cavitation is concentrated in the negative pressure zone,which isone of the main causes of oil film rupture.The phenomenon of cavitation is more obvious under small oil film pressure. Analysis of oil film cavitation lays the foundation for the research on the leaning and instability of floating ring bearing. 