The theoretical model of floating ring bearings under different conditions was built based on the Reynolds equation and random rough model to study the effect of surface roughness on the static characteristics of floating ring bearings.The oil film thickness and pressure distribution were obtained by solving the theoretical model with finite difference method.The results show that the bearing capacity of oil film is increased with the increasing of surface roughness,and the bearing capacity of inner oil film is larger than that of outer oil film.The leakage rate of floating ring bearings is decreased with the increasing of the surface roughness,and the leakage rate of inner oil film is larger than that of outer oil film.The friction power consumption is increased with the increasing of surface roughness and the friction power consumption of inner oil film is less than that of outer oil film