The utility model belongs to the lubricated field of decelerator specifically is a decelerator's lubricating arrangement. The problem of present large-scale reducing gear box gear and bearing be difficult to obtain the technique of sufficient lubrication is solved. A decelerator's lubricating arrangement, is including installing oil pump and the lever in locomotive reducing gear box box, said lever rotates and installs on the reducing gear box box, and the one end of lever is connected with the gyro wheel, the fixed one cam that is equipped with on the axletree of locomotive, gyro wheel and cam in close contact with, the other end of lever contacts with the plunger of oil pump, the oil inlet sealing connection of oil pump has the fuel sucking pipe, and the oil-out sealing connection of oil pump has the oil exit pipe, and the other end of oil exit pipe causes lubricating oil treats lubricated part. The utility model discloses the power of locomotive axletree has effectively been utilized to need not be equipped with extra power, consequently the utility model discloses it is very practical, only install and carry the work of lubricating oil inside just can the realization of present device to treating lubricated parts. Whole device simple structure is practical convenient.