In order to study the running performance of bearing when the water content of lubricating oil exceeds the standard,a sliding bearing bench was designed to study the effect of lubricating oil with different water content on sliding bearing performances,such as the temperature,friction torque and axial motion trajectory.It was found that when the water content of lubricating oil is low (below 0.5% in weight),it has little effect on the temperature,friction torque and axial trajectory of the bearing.But when the water content reaches a certain value (such as higher than 0.5% in weight),the repeatability of the axial trace is deteriorated,resulting in an unstable trend of the rotor operation.The results show that water content of lubricating oil will have a certain impact on the performance of the sliding bearing,and more accurate results need longterm experimental verification.