Theoretical and experimental studies were carried out for the stage of the gearbox lubrication failure,which is very common in daily running of highspeed railway locomotives,in order to find a reasonable failure mechanism and implement engineering applications.By engineering research and analysis,the major failure modes of gearbox lubrication were presented,which could be lubrication failure,wear of transmission system and sealing problem.By Raman spectrum and SEM,the corresponding discriminant method for each mode was presented according to the composition of the black particles from the gearbox oil.The actual projects proved the feasibility of these failure modes and identification methods.The final results of this study can provide a technical reference for the actual operation of highspeed rail maintenance.