Abstract: Using air and water as heat sources, the effects of different water temperature and water ratio on the heating performance of a double-heat pump water-cooled evaporator were experimentally studied. The water temperature is divided into 20℃ and 30℃ by the temperature controller, and the water proportion of the water-cooled evaporator is controlled by the valve at three levels of 0%, 67% and 100%. Four groups of different working conditions are set for comparative study on the heating performance, and the changes in the inlet and outlet temperature and heat production of the water-cooled evaporator under different working conditions are analyzed. The variation of heat produced by double heat source heat pump and single air source heat pump in frost removal period was studied. The study shows that compared with the single air source system, the average COP of the dual heat source system during the three operating conditions was 2.26, 2.61 and 2.54, respectively, which increased by 34.1%,51.7% and 47.7% compared with the single air source system.Among them, the COP of the system in working conditions 2 and 3 can reach the highest of 3.04 and 3.44. The water-cooled evaporator with high temperature and large water proportion has obvious replenishment effect on the system. Under the same water quantity, the system energy efficiency ratio with high water temperature is better. At the same time, the heat replenishment of water source can improve the frost formation problem of the system. Compared with the dual heat source system, the defrosting time of the single air source system is longer and the effect is poor. Under the action of forced defrosting, part of the system′s heat production is consumed, resulting in a lower COP than that of the dual heat source system.