The utility model provides an on -vehicle rail device that trades, characterized by: be equipped with power device on the locomotive chassis, the wheel pair of installation is located on the track below the locomotive chassis, and the carriage both ends are equipped with driver's cabin and locomotive control mechanism respectively, and the both sides on locomotive chassis are equipped with first and second rows of guide device that the structure is the same respectively, and the locomotive both ends are equipped with the rail respectively and import and export, is equipped with the first and second davit seats respectively at locomotive both ends top, and cartridge downthehole on the first and second davit seats is distinguished to first and second davits, first and second hand -drive block hang the dress respectively and on the first and second davit one end rings, at first and second hand -drive block's lower extreme, are equipped with first and second clamping rail pincers respectively, install pulley and hoist engine respectively on the railway carriage chassis, provide power for trading the rail device by on -vehicle hydraulic system, electric system, wire rope action on operation controlling means makes the hoist engine, under the cooperation of hand -drive block and clamping rail pincers, with the rail from the exit of carriage both ends take out of or remove into.