Aimed at the water inlet problem of thrust bearing lubricating oil under specific working conditions such as nuclear main pump and marine shafting,the influence of water invasion of lubricating oil on the lubrication performance of thrust bearing was studied with 46 lubricating oil and 68 lubricating oil as examples.The kinematic viscosity of lubricating oil with water mass fraction of 0,0.5% and 1.0% was obtained by viscosity test.The dynamic viscosity of lubricating oil before and after water content was characterized by viscosity-temperature curves.The viscosity-temperature relationship of lubricating oil was substituted into the lubrication calculation of thrust bearing.The minimum oil film thickness,temperature rise,flow and power consumption of the bearing under different water content were obtained,and the influence of water content on the takeoff speed of thrust bearing was analyzed.The results show that the water content of lubricating oil has a great influence on minimum oil film thickness and power consumption,and has little influence on temperature rise and flow.With the increase of water content,the minimum oil film thickness and power consumption decrease,the temperature rise increases and the flow decreases.The take-off speeds of the two lubricating oils are both below 50 r/min without water and with mass fraction of 0.5% water,and above 50 r/min with mass fraction of 1.0% water,which indicates that the take-off speed increases with the increase of water content.