The invention discloses a spiral wound heat exchanger special for a double-heat pump water heater. The spiral wound heat exchanger consists of two parts, i.e. an outer metal pipe and an inner metal pipe, wherein the outer metal pipe is closely wound on the outer wall of the inner metal pipe. Two groups are required to be used in a double-heat pump spiral wound water heater, wherein the inner pipe of the spiral wound heat exchanger in one group is required to be used as a condenser of a first heat pump closed-loop circulation system, and the outer pipe is used as an evaporator of the first heat pump closed-loop circulation system; the inner pipe of the spiral wound heat exchanger in the other group is used as a condenser of a second heat pump closed-loop circulation system, a low-temperature water inlet port of the outer pipe is communicated with a tap water pipeline, and the other port is a hot water outlet. According to the spiral wound heat exchanger special for the double-heat pump water heater, double heat pumps of the double-heat pump spiral wound water heater can be conveniently and efficiently utilized for secondary heating, and tap water at sufficiently high temperature can be obtained at one time.