When the humidifier is working, the tap water that has been filtered multiple times directly enters the water tank. The circulating water pump continuously delivers the water directly to the water distribution system at the top of the humidifier, evenly spraying the water on the high-efficiency evaporation material. The water seeps down from the top of the high-efficiency evaporation material and is absorbed by the high-efficiency evaporation material to form a uniform water film. The air flows rapidly through the axial flow fan. When the dry air is sucked into the humidifier by the fan, some of the water contacts with the dry air and absorbs heat, causing gasification and increasing the humidity of the air. The other part of the water that has not evaporated flows back to the water tank and is reused by the circulating water pump. When the water level drops to a lower level, the float valve automatically opens to replenish water to the water tank, and automatically closes when the water is full.