Wet curtain fan with high efficiency and energy saving, wo soil negative pressure ventilation cooling system is with the use of fan and water, reproduce the natural evaporation of moisture artificially cooling the physical process, the power consumption is only 1/10 of traditional air conditioning. The ventilation in the mutual cooperation of the entire system, exhaust fan exhaust heat, exhaust, quickly go indoor plants produce peculiar smell, avoiding emissions and odor stimulation on plant. The fastest indoor air can be updated once in a minute, this is a general air conditioning can not be achieved. Improve work efficiency to solve the heat and oxygen deficiency caused the plants to die. Products using the water curtain cooling can not only solve the greenhouse problem is even more hot and cool in the water evaporation, a negative oxygen ion, increase the oxygen content in the air. System using water as refrigerant, no pollution to the environment in the manufacturing and using process, water addition to lowering air humidity, but also have clean outside air carrying dust and particles. Efficient circulation of fresh air.