The invention discloses a heat pump water heater, which comprises a compressor, a double-pipe heat interchanger, an outdoor evaporator and a cold storage heat exchange, wherein the compressor, the double-pipe heat interchanger and the outdoor evaporator are sequentially connected and form a circuit; the cold storage heat exchanger is used for converting liquid refrigerant into gaseous refrigerantand is parallel connected with the outdoor evaporator in the circuit; the cold storage heat exchanger has inner and outer two layers of barrel structures; and a heat insulating material is arranged between the inner and outer two layers of barrel structures. The heat pump water heater of the invention can improve resource utilization rate, is environmentally-friendly and pollution-free, adopts anice cold storage mode, can reduce water temperature to 2 to 5 DEG C through freezing by ice, can realize low-temperature air supply, reduces the power and equipment cost of an air conditioner terminal. In addition, the heat pump water heater has multiple functions, operates in ice-making, ice-melting, cooling, ice-meting cooling and heating modes, and can meet demands of various loads.