A heat pump hot-water supply device and a method for controlling a heat pump hot-water supply device are provided. The heat pump hot-water supply device may include a first refrigerant cycle, in which a first refrigerant may circulate, the first refrigerant cycle including a first compressor, an outdoor heat exchanger, and a first expansion device; a second refrigerant cycle, in which a second refrigerant may circulate, the second refrigerant cycle including a second compressor and a second expansion device; a water-refrigerant heat exchanger to which the first refrigerant compressed in the first compressor and the second refrigerant compressed in the second compressor may be introduced; a water introduction path coupled to a first side of the water-refrigerant heat exchanger and into which supplied water may be introduced; and a water discharge path coupled to a second side of the water-refrigerant heat exchanger and from which the water heat-exchanged in the refrigerant heat exchanger may be discharged.