Abstract: To investigate the influences of key parameters of threshing and redrying on the quality of tobacco leaf modular from Yunnan, Wenshan leaf modular with a moderate "fresh-sweetness scent" style leaf were studied. On the basis of Box-Behnken Design (BBD) principle, the conditions of threshing and redrying were optimized by adopting the response surface methodology and taking the moisture content in conditioning, conditioning temperature and redrying temperature as major influencing factors and the moisture content and CCUI values of redried strips as response values, and the corresponding prediction mathematical models were established. The results showed that the relationships between the moisture content and CCUI values of redried strips and key technological parameters were all consistent with the quadratic equation model (the values of R² were 0.945 1 and 0.855 7 respectively). Redrying temperature affected both the moisture content and CCUI values of the strips greatly. The optimal parameters were moisture content during conditioning at 17.5%, conditioning temperature at 58.0 ℃, and redrying temperature at 406.0 ℃. Under the optimized condition, the moisture content in the redried strips was 9.627% and its CCUI value was 0.851, which increased by 3.780% compared with that of regular production. The intrinsic quality of redried strips was significantly improved (P < 0.01). The percentage of large-sized strips and the stem contents in the strips decreased significantly. The aroma notes of hay-like, pure-sweetness and green scents and sensory quality of the redried strips were more prominent. It indicated that properly raising conditioning temperature and redrying temperature were more beneficial in reducing the percentage of large-sized strips, increasing the percentage of medium and small-sized strips, and enhancing the style characteristics and the sensory quality of tobacco leaf modular from Yunnan.