The two-phase flow model of the oil-air lubrication system was built by Fluent software based on two phase flows theory.The state of oil-air two-phase flow after flowing through direct jet nozzle and inner ring jet nozzle were analyzed.For the inner ring jet nozzle,the influences of the key structure parameters,the angle between the vertical pipe and the inclined pipeline and the nozzle exit structure to oil/air phase distribution in bearing were also analyzed.The simulation results show that the inner ring jet nozzle has better lubricating effect than the direct jet nozzle,the necessary amounts of oil and air are less.Small angle between the vertical pipe and the inclined pipeline is conducive to maintaining the annular flow.The design of sudden expansion pipe alleviates the nonuniformity caused by oil/air fluctuation.