The structure of the diesel locomotive includes five parts: the engine, the transmission, the body and the frame, the bogie and the auxiliary device. Auxiliary devices include: 1. fuel supply system; 2. preheating and cooling water system; 3. oil system; 4. air line, braking and sanding system; 5. electronic control and lighting system. In addition, there are auxiliary drives, signal devices, ventilation devices, cold-proof devices, fire extinguishers and common tools.