The technology of de-enzyming of tea leaf by hot water for the purpose of minimizing the caffeine in tea was discussed. Be combined with dehydration, rolling and drying, the tea had the style of the traditional roasting green tea and the caffeine contents were reduced as high as 67%. The major constituents could be as high as 82%. This leaf dredging up machine is characterized by the advantage of simple structure, convenient handing, high rate of taking off caffeine, and saving water and energy.