Wheel-rail vibration could be caused by the surface irregularity of wheel-rail material, and the third body me-dium also played an important role in the evolution of rolling contact fatigue (RCF) under the vibration con-dition. This study aims to investigate the effect of vibration amplitude and axle load on the rail rolling contact fatigue (RCF) under water condition using a twin-disc test machine. Results indicated that the average friction coefficient and the plastic deformation depth decreased, while the surface hardness, wear rate, surface damage and the crack damage degree all increased with the increase in both the axle load and the vibration amplitude. Applying vibration into rollers interface would increase the entering water flow and accelerate the crack propagation, forming crack intersections which tended to generate material spalling, leading to the catastrophic increase in the wear rate and the proportion of crack propagating in transgranular manner.