A thermal management system, the thermal management system having a coolant system, wherein the coolant system includes a battery circuit and a heating/cooling circuit; a second flow channel of a first heat exchanger, a battery heat exchanger, and a first pump form a part of the battery circuit, while a heater, a radiator, and a second pump form a part of the heating/cooling circuit; a first valve device turns on or blocks the battery circuit and the heating/cooling circuit; the coolant system comprises a connection portion, and the connection portion turns on or blocks the battery circuit and the heating/cooling circuit.