Abstract: The present application provides a heat pump system. The heat pump system comprises a main circulating refrigerant loop, an auxiliary circulating refrigerant loop, and a refrigerant management system; the main circulating refrigerant loop comprises a main compressor, a first main heat exchanger, a main throttling device, and a second main heat exchanger, the main compressor is configured to allow a refrigerant in the main circulating refrigerant loop to circulate in a main circulating refrigeration working condition flow direction or circulate in a main circulating heating working condition flow direction. The auxiliary circulating refrigerant loop comprises an auxiliary compressor, a first auxiliary heat exchanger, an auxiliary throttling device, and a second auxiliary heat exchanger; the auxiliary compressor is configured to allow a refrigerant in the auxiliary circulating refrigerant loop to circulate in an auxiliary circulating heating working condition flow direction.