The invention discloses a composite cooling pack for an internal-combustion motor train unit. The composite cooling bag for the internal-combustion motor train unit is characterized by comprising an air pressurization and oil cooling pack and a water cooling pack which are arranged on both sides of an engine. The air pressurization and oil cooling pack comprises a fan box I, a cooling unit I fixedly arranged at the front end of the fan box I, and a filter unit I fixedly arranged at the front end of the cooling unit I; fan barrels which are used for accommodating fan blades I are arranged inside the fan box I, and the air pressurization and oil cooling pack is fixed onto a train bottom mounting rack through a mounting seat I arranged on the fan box I. The water cooling pack comprises a fan box II, a cooling unit II fixedly arranged at the front end of the fan box II, and a filter unit II fixedly arranged at the front end of the cooling unit II; fan barrels which are used for accommodating fan blades II are arranged outside the fan box II, and the water cooling pack is fixed onto the train bottom mounting rack through a mounting seat II arranged on the fan box II. The composite cooling pack for the internal-combustion motor train unit cools the engine in a composite cooling pack mode and has the advantages such as reasonable structure, small space occupation and high cooling efficiency.