Abstract: Pile-fermentation using the automatic fermentation tank( patent number: 200920111698. 9) to deal with Yunnan sun-dried green tea was studied and optimized in this paper. The optimum technological parameters were obtained by taking moisture,germ dosage and turnover cycle as the three factors to carry out the orthogonal experiment. At the same time,the quality of pu-erh tea obtained from the automatic fermentation tank and traditional method was compared based on the analysis of chemical components and sensory evaluation. The results showed that the aroma and taste of pu-erh tea was best formed after fermentation for 19 days when the moisture was 27%,germ dosage was 100 mL /100 kg,and turnover cycle was once every 2 days. It provided the experimental data for application of automatic fermentation tank.