By considering the influence of surface roughness,the mathematical model was constructed for water-lubricated bearings with different non-metallic lining materials,including nitrile rubber(NBR),Thordon,Tenmat and ultra-high molecular polyethylene(UHMWPE),and the water film thickness equation was deduced.The lining deformation,water film thickness and pressure of the four lining materials were investigated by finite difference method when considering the actual surface roughness,the variation of minimum water film pressure and bearing capacity with rotating speed were analyzed,and the calculated results were compared with those of the smooth surface bearings.The results show that considering the surface roughness,the lining deformation and water film thickness of the water-lubricated bearings exhibit a continuous wave-like distribution,the lining deformation and the minimum water film thickness decrease,while the water film pressure has a slight local mutation,the maximum water film pressure increases,and the bearing capacity decreases.The deformation and the minimum water film thickness follow the descending order of NBR,Thordon,Tenmat and UHMWPE,and the water film pressure follows the descending order of UHMWPE,Tenmat,Thordon and NBR.Under the same working conditions,the lubricating water film is relatively easier to be formed for NBR lining material than the other three lining materials,while the system can bear a large bearing capacity when using UHMWPE as lining material.This study can provide reference for the material selection,processing and assembly of water-lubricated bearings.