A thermal management system, wherein the thermal management system comprises a refrigerant system and a coolant system, and a refrigerant of the refrigerant system and a coolant of the coolant system are isolated from each other without communication; the refrigerant system comprises a compressor, a first throttling device, a second throttling device, a first heat exchanger, a second heat exchanger and a first valve device; the second heat exchanger comprises a first end port and a second end port, the first throttling device is in communication with the second end port of the second heat exchanger, a refrigerant inlet of the first heat exchanger is in communication with an outlet of the compressor, a refrigerant outlet of the first heat exchanger is in communication with the first valve device, the compressor is in communication with the first valve device through the first heat exchanger, the first heat exchanger is in communication with the first throttling device through the first valve device, and the first end port of the second heat exchanger is in communication with a suction port of the compressor or the refrigerant outlet of the first heat exchanger through the first valve device; and the coolant system comprises a third heat exchanger and a first pump; the thermal management system further comprises a fourth heat exchanger, the fourth heat exchanger comprises a first flow passage and a second flow passage, an inlet of the first flow passage of the fourth heat exchanger is in communication with the second throttling device, an outlet of the first flow passage of the fourth heat exchanger is in communication with the suction port of the compressor, the second flow passage of the fourth heat exchanger is in communication with the third heat exchanger and the first pump, and the coolant system and the refrigerant system are allowed to exchange heat in the fourth heat exchanger; and in a deicing mode of the thermal management system, the second heat exchanger is in communication with the first flow passage of the fourth heat exchanger through the second throttling device, the refrigerant system further comprises a fifth heat exchanger and a third throttling device, the third throttling device is in communication with an inlet of the fifth heat exchanger, an outlet of the fifth heat exchanger is in communication with the suction port of the compressor; and the thermal management system further comprises an air conditioning cabinet body, the first heat exchanger and the fifth heat exchanger are arranged in the air conditioning cabinet body, the thermal management system is characterized in that the fourth heat exchanger and the fifth heat exchanger are connected in parallel between the second end port of the second heat exchanger and the suction port of the compressor. the refrigerant system comprises a compressor, a first throttling device, a second throttling device, a first heat exchanger, a second heat exchanger and a first valve device; the second heat exchanger comprises a first end port and a second end port, the first throttling device is in communication with the second end port of the second heat exchanger, a refrigerant inlet of the first heat exchanger is in communication with an outlet of the compressor, a refrigerant outlet of the first heat exchanger is in communication with the first valve device, the compressor is in communication with the first valve device through the first heat exchanger, the first heat exchanger is in communication with the first throttling device through the first valve device, and the first end port of the second heat exchanger is in communication with a suction port of the compressor or the refrigerant outlet of the first heat exchanger through the first valve device; and the coolant system comprises a third heat exchanger and a first pump; the thermal management system further comprises a fourth heat exchanger, the fourth heat exchanger comprises a first flow passage and a second flow passage, an inlet of the first flow passage of the fourth heat exchanger is in communication with the second throttling device, an outlet of the first flow passage of the fourth heat exchanger is in communication with the suction port of the compressor, the second flow passage of the fourth heat exchanger is in communication with the third heat exchanger and the first pump, and the coolant system and the refrigerant system are allowed to exchange heat in the fourth heat exchanger; and in a deicing mode of the thermal management system, the second heat exchanger is in communication with the first flow passage of the fourth heat exchanger through the second throttling device, the refrigerant system further comprises a fifth heat exchanger and a third throttling device, the third throttling device is in communication with an inlet of the fifth heat exchanger, an outlet of the fifth heat exchanger is in communication with the suction port of the compressor; and the thermal management system further comprises an air conditioning cabinet body, the first heat exchanger and the fifth heat exchanger are arranged in the air conditioning cabinet body, the thermal management system is characterized in that the fourth heat exchanger and the fifth heat exchanger are connected in parallel between the second end port of the second heat exchanger and the suction port of the compressor.