In order to reveal the effect of surface roughness on the lubrication performance of marine water lubricated polymer bearings,theoretical research on elastohydrodynamic lubrication of water lubricated bearings was conducted.A hybrid lubrication model of water lubricated bearing considering the roughness and elastic deformation of lining material was established and verified by simulation.The influence of inner liner roughness peak on water film thickness,water film pressure distribution and bearing capacity was analyzed.The results show that the increase of liner roughness will slow down the increase ratio of water film thickness during the increase of rotating speed,so that the bearing needs higher rotating speed to enter the hydrodynamic lubrication state.Reducing the roughness of the bearing lining can effectively reduce the take-off speed of the bearing,accelerate the process of the bearing from mixed lubrication to hydrodynamic lubrication,reduce the local contact between the bearing and the journal,and reduce the possibility of abnormal vibration and noise of the bearing.This research reveals the mechanism of the influence of the change of the inner liner roughness on the lubrication characteristics of the bearing,and provides a theoretical reference for the optimal design of the water lubricated bearing.