The utility model aims at providing a locomotive winter diesel heating system, in order to solve the problem of that the diesel locomotive is difficult to start in winter. The utility model includes a starting oil tank pair (2) which contains the high mark diesel; the starting oil tank pair (2) is communicated with an oil inlet pipe (3) and an oil return pipe (6); the oil inlet pipe (3) is communicated with an oil inlet three-way valve (4); the oil return pipe (6) is communicated with an oil return three-way valve (7). After the high mark diesel is adopted to start the diesel engine, the tail gas discharged from the water tank and the gas outlet pipe of the locomotive starts to get the heat after the locomotive drives for 5-10km; at this time, only the heat at the two positions are required to lead in to heat the main oil tank to meet the normal driving. The utility model mainly solves problems of oil-freezing caused by locomotive parking in the night, traffic jam on the road, locomotive repairing on the way, and long-time locomotive parking.