The invention relates to the field of heat exchange equipment provided with a tube-shaped channel, and in particular relates to a recovery device for preparing fresh water and purifying air by utilizing waste heat, and a using method of the recovery device. The recovery device for preparing the fresh water and purifying the air by utilizing the waste heat comprises a bracket (1), and is characterized by further comprising an evaporation-condensation interchanger (2), a sewage waste heat humidifying and heating device (3) and a natural ventilation machine (4), wherein the evaporation-condensation interchanger (2) and the sewage waste heat humidifying and heating device (3) are arranged in the bracket (1); the sewage waste heat humidifying and heating device (3) is arranged above the evaporation-condensation interchanger (2); and the natural ventilation machine (4) is arranged above the sewage waste heat humidifying and heating device (3). The using method of the recovery device for preparing the fresh water and purifying the air by utilizing the waste heat is characterized in that condensate water is separated out after heat exchange and condensation are carried out on the ambient air. The recovery device is simple in structure, convenient to use, high in recovery efficiency and wide in application scope.