The elastohydrodynamic lubrication model of oilwater twophase flow of rolling mill oil film bearing was established,and the effect of surface waviness on the lubrication performance of rolling mill oil film bearing was analyzed by using multigrid method and Fortran program.The results show that the effect of surface waviness on the rolling mill oil film bearing cannot be ignored and it is unfavorable to the bearing lubrication performance.Considering the effect of surface waviness,a significant fluctuation in the contact center is generated,the maximum pressure is increased and the minimum film thickness is decreased,which leads to the decrease of lubricating properties.With the increasing of surface waviness amplitude and wavelength,the fluctuations is more significant in contact area.In a certain range,with the increasing of water content in the oilwater twophase flow,the pressure and film thickness are increased,thus the lubricating capacity is enhanced.