Abstract: The paper states the successful result by using the microcomputer system to control the environmental conditions for withering and twisting the green leaves of Wulong tea. The temperature to be controlled is within the limits of 20-28℃ ± 0.2℃ and the relative humidity within 55-75% ± 3-5%.The whole system effectively controlled the environmental conditions for withering and twisting the green leaves of Wulong tea in order to guarantee the stable quality and process the high grade tea all the year round without any time limit .The experiment showed that about 50% of time of withering and twisting was shortened by this microcomputer system.Meanwhile , it was greatly reduced the labour intensity ;the quality of Wulong tea was 1-2 grades higher than traditional processing method and the price of dry Wulong tea will raise RMB 2-3 yuan per kg. In consequence, it will promote the export capacity and earn more foreign exchange.The experiment showed that this microcomputer system can also be used in the environmental controls for processing and preserving other farm products.