High-pressure spray cooling system is the use of ambient heat absorbed by water molecules evaporate to achieve lower ambient temperature, ie, unsaturated air by evaporation and water to cool. When the moisture contained in the air does not reach saturation, the water becomes vapor evaporated into the air, while the evaporation of water, the heat absorption of the air, the air temperature drops, the relative humidity of the air increases. Usually every 1g of water evaporation, cooling air can make about 2.46 degrees of hepatic C. The lower the relative humidity of the air, the higher the temperature, the greater the cooling magnitude but, on the contrary, the greater the relative humidity of the air, the lower the temperature, the magnitude of the scriptures will be smaller. When the relative humidity of the air more than 95%, the temperature at 25 degrees C, the cooling effect is not obvious. According to the actual test, the indoor air relative humidity is 77% and the temperature at 27.5 ° C when the ventilation in general, the spray system is running four minutes, measured a temperature of 22 to 23.5 ° C, relative humidity of the indoor air 93 to 95 % RH. Temperature decrease of 4 degrees, the humidity increases 18 ~ 20% RH, (this is the rainy tested outdoor air relative humidity is 85 ~ 90%), temperature of 27 to 28 degrees C), when the indoor temperature is 38 ° C , the relative humidity of 55% RH, the system runs 3 minutes, the measurement temperature was 31.8 degrees, 87.5% relative humidity, the temperature dropped 6.4 ° C, humidity increases 32.5% RH, according to the results of the test data, a reduced temperature, humidity increased 5% RH.