Abstract: Abstract: Enzyme deactivation is the key process of green tea primary processing, which has significant effects on the color, aroma, taste and other flavor quality of green tea. In the process of enzyme deactivation, high temperature is used to rapidly destroy enzyme activity to stop the oxidation of polyphenols and prohibit leaves to become red, and to evaporate water in the leaves to increase flexibility of the leaves and create opportune conditions for the subsequent modeling. In addition, the volatilization and conversion of some undesirable low-boiling aromas occurs under high-temperature treatment, and meanwhile, the formation of some new special aromas improves the tea fragrance. Different ways of enzyme deactivation show different effects on the various quality materials of fresh leaves and the quality of made tea, for example, microwave deactivation of enzyme can rapidly inactivate enzymes, and make the color green, but the taste and fragrance are poor; enzyme deactivation with hot air can make the excellent fragrance due to high temperature, but can easily lead to the coke side and focal point; traditional roller deactivation of enzyme can make high fragrance and pure taste of tea, but it is not easily controlled. For this reason, based on roller deactivation of enzyme, the machine used in the article combines the advantages of different manners of enzyme deactivation. Electromagnetic roller-hot air coupling machine of enzyme deactivation is heated by electromagnetic heat technology, which significantly improves energy efficiency and heating stability. The thermal efficiency of the enzyme deactivation machine is more than 45%, and the temperature fluctuations can be controlled under ±3℃. The digital regulation system is used to improve the uniformity and stability of enzyme deactivation, and automatic sending and continuous production of leaves can effectively reduce the labor and employment. The coupling technology between roller deactivation of enzyme and hot air deactivation of enzyme makes green color and overflowing fragrance for leaves, and the sensory quality of made tea is better than microwave deactivation of enzyme and electric heating tube roller deactivation of enzyme. The structure composition and technical characteristics of this enzyme deactivation machine (Patent number: ZL201410473680.9) were introduced in this article. Then the parameters of the electromagnetic roller-hot air coupling enzyme-deactivation of green tea were optimized. Based on the results of previous single factor experiments, taking main biochemical compositions' contents and sensory evaluation scores of made tea as investigation indices, Box-Behnken design was used to optimize the parameters of enzyme deactivation process (temperature of hot air, wind speed of hot air, temperature of front part, etc.) with electromagnetic roller-hot air coupling machine. And the new technology of enzyme deactivation was compared with electric heating tube roller enzyme deactivation, microwave deactivation of enzyme, hot air enzyme deactivation and electromagnetic heat roller enzyme deactivation. The results showed that when the leaf weight of enzyme deactivation was 150 kg/h, the optimal combination parameters of electromagnetic roller-hot air coupling machine of enzyme deactivation were determined as follows: temperature of hot air was 104℃, blower speed of hot air was 920 r/min and temperature of front part was 270℃. The taste, color and aroma of green tea made with these parameters were the best and sensory quality score was 91.0, which was 2.7-4.0 point higher than other methods of enzyme deactivation. And the contents of tea polyphenols, amino acids, soluble sugar, catechins, caffeine and flavonoids of leaves after enzyme deactivation reached 13.849%, 2.057%, 8.412%, 9.724%, 2.172% and 1.336%, respectively. The energy consumption was reduced by 1/2 compared with electric heating tube roller enzyme deactivation, and the thermal efficiency was up to 45%-55%. The deficiency of traditional roller enzyme deactivation can be overcome with electromagnetic roller-hot air coupling enzyme deactivation technology, which will provide guidance for the production of green tea.