The utility model discloses a transaxle cooling system of no oil tank, including hydraulic system (1), solenoid valve (2), fan unit (3), prevent inhaling sky check valve (4), radiator block (5), bridge oil drain pump organizes (8), front axle (6) and rear axle (9), hydraulic system (1) is prevented inhaling sky check valve (4) oil return way and is flowed in fan unit (3) respectively to solenoid valve (2), fan unit (3) with prevent inhaling sky check valve (4) fuel feeding, solenoid valve (2) are your bi -pass normally closed valve, and wheel limit temperature sensor passes through the controller electricity and connects this solenoid valve (2) and control its break -make, radiator block (5) including preceding, rear axle radiator, and bridge oil drain pump group (8) is including preceding, rear axle oil drain pump, and front axle (6), rear axle (9) respectively through preceding, rear axle oil drain pump forward, behind the rear axle radiator fuel feeding. This system need not oil tank and complicated valves, can dispel the heat by intelligent hydraulic pressure, and heat dissipation oil is driving the circulation of inner bridge portion.