The effect of water mixed with lubricants on the thermal elastohydrodynamic lubrication of oil film bearing of rolling mill was studied.The mathematical model of oilwater twophase flow and mathematical equations of thermal elastohydrodynamic lubrication of the oil film bearing of rolling mill were built.The multigrid and multigrid integration method were used to solve the above equations，and the variation of lubricant film pressure and film thickness with the water content，spindle speed and rolling force was discussed.The results show that，compared with pure oil lubrication，oilwater twophase fluid lubrication has better lubricating properties.With the increase of water content，the film thickness is increased and the carrying capacity is enhanced.With the increase of spindle speed，the film thickness is increased，carrying capacity is reduced.With the increase of rolling force，the film thickness is decreased，the carrying capacity is enhanced.In the lubricated condition of oilwater twophase flow，the influence of thermal effect on the elastohydrodynamic lubrication of oil film bearing can not be ignored.