The invention relates to a water evaporative environmental-protection refrigeration air conditioner and a refrigeration method thereof. The water evaporative environmental-protection refrigeration air conditioner comprises an insulating shell, a water supply device, a vacuum evaporator, a dry cooling cavity and a pumping exhaust fan, wherein the water supply device is arranged on the bottom part of the insulating shell and is used for supplying working medium water; the vacuum evaporator comprises water sucking grid curtain and a cool air cavity, the water sucking grid curtain is partially arranged in the water supply device, and the cool air cavity is arranged on the upper end of the water sucking grid curtain and forms a certain space by enclosing all the sides of the inner shell thereof; the dry cooling cavity is arranged between the insulating shell and the vacuum evaporator and is used for changing indoor air into precooled air; and the pumping exhaust fan is arranged on the upper surface of the vacuum evaporator and is used for discharging the cool air in the cool air cavity. The water evaporative environmental-protection refrigeration air conditioner and the refrigeration method thereof have simple structure and can reduce temperature and effectively increase the humidity of the indoor air at the same time.