The lubrication performance of thrust bearings was studied in the light of the complex working conditions such as time-varying load,water intrusion of lubricating oil and axial tilt of nuclear main pump shafting.The structure and working condition of thrust bearing of nuclear main pump shafting were analyzed,and the calculation model of lubrication performance of thrust bearing was established.For the variable load conditions during the operation of the nuclear main pump,the minimum oil film thickness,temperature rise,friction torque and power consumption of thrust bearing under variable load conditions were calculated with different load as input parameters.According to the water intrusion condition of lubricating oil,No.68 lubricating oil containing 1% seawater was selected to analyze the lubrication performance of thrust bearing when the lubricating oil was mixed with atomized seawater in the air.A calculation model for the lubrication performance of thrust bearing with axial tilt was established,and the lubrication performance of thrust bearing with axial tilt from 1′ to 20′ was calculated.The results show that the minimum oil film thickness decreases with the increase of load and reaches the minimum value when load is 2 000 kN,the temperature rise increases with the increase of load,both friction torque and power consumption increase with the increase of load.After seawater intrusion,the viscosity of lubricating oil will decrease,thereby affecting the bearing capacity of thrust bearing.The balance block support structure has a good load balancing effect on the thrust bearing,and the allowable axis inclination can reach 10′.