This article presents detailed comparison between frictional characteristics of such friction pairs as Si3N4 axle bush/SiC axle journal, SiC axle bush/Si3N4 axle journal, SiC axle bush/SiC axle journal by means of the bench test on water-lubricated ceramic sliding bearing The theory is gained that Si3N4 axle bush/SiC axle journal cannot match each other for the coefficient of thermal expansion, and SiC axle bush/SiC axle journal is the most suitable fiction pair with perfect capability to complete water-lubrication, especially in the conditions of major diameter, high power and high speed. In addition, considering the ceramic characteristics, a compatible structure is designed in this paper to solve the problems caused by stress concentration. Thus the safety and reliability of this bearing are improved.