The invention relates to a air-cooled cold water heat pump air-conditioner hot water system which comprises a air-conditioner hot water main system, wherein the air-conditioner hot water main system comprises a compressor, a four-way reversing valve component, a fin heat exchanger, a blower component, an electronic expansion valve component, an air-conditioner side reservoir, an air-conditioner side heat exchanger, a gas-liquid separator, a hot water heat exchanger, a hot water side reservoir and a non-return valve which are in connection through a pipeline, wherein the compressor is a general compressor or an enhanced vapor injection (EVI) compressor. The hot water system not only realizes the functions of refrigeration, heating, air-conditioner refrigeration heat recovery and separated water heating, but also achieves two defrosting manners so as to solve the defrosting problem under different application conditions; meanwhile, as the EVI technology is adopted, the hot water system can normally carry out heating or water heating under an extremely-low temperature environmental of subzero 5 to subzero 25 DEG C, and the heating water temperature can reach 55 DEG C, even 60 DEG C to the highest; and the hot water system, with the characteristic of energy conservation, can replace both electric water heaters and the gas water heaters.