A cooling system, applied to an electric motor, wherein the electric motor comprises a stator support and a rotor support, the stator support is dynamically sealingly connected to the rotor support to form ventilation chambers, the ventilation chambers are respectively arranged at two ends of the electric motor in an axial direction, first ventilation holes (a) are formed at two ends of the stator support in the axial direction respectively, and the cooling system comprises a flow-confluence chamber, arranged in a circumferential direction of the stator support; an accommodating chamber, arranged in the circumferential direction of the stator support; wherein the accommodating chamber is located at an inner side of the flow-confluence chamber in a radial direction and communicates with the flow-confluence chamber, and the first ventilation holes (a) are located outside the accommodating chamber; a heat exchanger, arranged in the accommodating chamber; a circulating fan, arranged in the circumferential direction of the stator support and located at a side of the stator support in the axial direction, wherein the circulating fan has an air inlet and an air outlet; characterized in that after cooling air flows out of the air outlet of the circulating fan, a part of the cooling air enters one of the ventilation chambers which is closer; the other part of the cooling air enters the other of the ventilation chambers through the first ventilation holes (a), which are respectively formed at the two ends of the stator support in the axial direction, the two parts (W1,W2) of the cooling air flow over a heat-generating member in the electric motor, and then enter the air inlet of the circulating fan via the flow-confluence chamber, the heat exchanger and the accommodating chamber; wherein two or more circulating fans are distributed to be spaced apart from one another in the circumferential direction of the stator support; two or more accommodating chambers are distributed to be spaced apart from one another in the circumferential direction of the stator support, and correspond to the two or more circulating fans in a one-to-one correspondence, and the heat exchanger is arranged in each of the accommodating chambers. a flow-confluence chamber, arranged in a circumferential direction of the stator support; an accommodating chamber, arranged in the circumferential direction of the stator support; wherein the accommodating chamber is located at an inner side of the flow-confluence chamber in a radial direction and communicates with the flow-confluence chamber, and the first ventilation holes (a) are located outside the accommodating chamber; a heat exchanger, arranged in the accommodating chamber; a circulating fan, arranged in the circumferential direction of the stator support and located at a side of the stator support in the axial direction, wherein the circulating fan has an air inlet and an air outlet; characterized in that after cooling air flows out of the air outlet of the circulating fan, a part of the cooling air enters one of the ventilation chambers which is closer; the other part of the cooling air enters the other of the ventilation chambers through the first ventilation holes (a), which are respectively formed at the two ends of the stator support in the axial direction, the two parts (W1,W2) of the cooling air flow over a heat-generating member in the electric motor, and then enter the air inlet of the circulating fan via the flow-confluence chamber, the heat exchanger and the accommodating chamber; wherein two or more circulating fans are distributed to be spaced apart from one another in the circumferential direction of the stator support; two or more accommodating chambers are distributed to be spaced apart from one another in the circumferential direction of the stator support, and correspond to the two or more circulating fans in a one-to-one correspondence, and the heat exchanger is arranged in each of the accommodating chambers.