The invention discloses a thermal l management system of a commercial vehicle power battery. The thermal management system comprises a battery liquid-cooling system, a heat dissipation system and a heating system, wherein the battery liquid-cooling system comprises an ethylene glycol aqueous solution circulation system and a refrigerant circulation system, the ethylene glycol aqueous solution circulation system comprises a compensation water tank, a power battery and a first water pump, and the refrigerant circulation system comprises an expansion valve, a condenser and a compressor. The additionally-arranged heat dissipation system is connected in parallel with an engine cooling system outside an intelligent cooling management system, and an air suction type electronic fan of the intelligent cooling management system is used for blowing air and cooling; and compared with an original system, the novel power battery thermal management system has the advantages of relatively small change and more energy saving, and the battery temperature difference can be more uniform.