Abstract: In order to reduce the energy consumption of air conditioning system in cigarette factory, the system was upgraded with hot water wet-membrane humidification and temperature/humidity independent control technologies. A fresh air humidity regulating unit was set up, which included a new type wet-membrane humidifier for humidifying, and a small-size surface cooler for dehumidifying. Coming from that, the fresh air was mixed with recirculated air. The temperature of the mixed air was regulated by an air handling unit (AHU) before entering into workshop. The results showed that:1) The control precision of the upgraded air conditioning system satisfied the requirements of workshop with the maximum temperature difference of 1.07℃ and the maximum humidity difference of 2.06% RH. 2) The steam consumption of air conditioning system reduced by 50.56%, the energy consumption of refrigeration decreased by 19.41%, totally 2.104 1 million RMB yuan/year were saved. This technology effectively avoids the "cold-heat offset" phenomenon in an air conditioning system under full air volume running conditions and well adapts to the weather variations throughout the year.