The invention relates to a novel cooling system of a hybrid power excavating machine. In the invention, a water radiator, an integrative radiator and an air-to-air intercooler are designed as an independent circulation loop respectively, thus ensuring respective working temperature thereof within respective permission scope. The integrative radiator and the water radiator are successively arranged from outside to inside, and are welded with the air-to-air intercooler respectively, thus effectively solving the problems of poor sealing, ventilation leakage and the like between the radiators, improving the cooling effect of the cooling system, and reducing space arrangement. In addition, the complete machine system is simple, reliable and practical.