The invention relates to a novel oil tank for a hydraulic power pack. The novel oil tank comprises a tank body. Partition cavities are formed in the four side walls of the tank body. The partition cavities are filled with thermal grease. Heat-conducting fins are arranged on the outer sides of the four side walls of the tank body. A vertical partition plate is arranged inside the tank body. The partition plate is provided with a through groove. Transverse magnetic attraction pieces are arranged at the connecting positions of the upper end and the lower end of the partition plate and the tank body separately. The tank body is divided into an oil return cavity and an oil outlet cavity by the partition plate. The oil return cavity is provided with an oil return port and an oil filling port. A filtering device is arranged under the oil return port. The filtering device is connected with a hydraulic oil cooler. The oil outlet cavity is provided with an oil outlet. An oil outlet filter element is arranged under the oil outlet. The novel oil tank for the hydraulic power pack comprises a dual-cooling system and the partition plate. No extra energy consumption exists, and the radiating effect is quite good. The filtering device, the oil outlet filter element and the magnetic attraction pieces at the two ends of the partition plate can filter and clear oil, and normal operation of the hydraulic system is effectively maintained.