Abstract: In order to investigate the effects of Maillard reaction time on the aroma of tobacco bud fermentation broth，the tobacco flavor was prepared and optimized by Maillard reaction time control after the tobacco bud was fermented by high-active aroma-producing yeast，and the flavor was analyzed by principal component analysis and sensory evaluation. The results showed that: by simultaneous distillation and extraction，the kind of aroma components in the flavor sample of 8 h Maillard reaction was 45，and the kind of aroma components in the flavor sample of 12 h Maillard reaction was 38，and the kind of aroma components in the flavor sample of 16 h Maillard reaction was 45，and the kind of aroma components in the flavor sample of 20 h Maillard reaction was 42，including alcohols， aldehydes，acids and esters，ketones，furans and pyridine etc. After the tobacco bud fermentation broth treated by Maillard reaction with different time，flavor components were analyzed by principal component analysis and it showed that there were significant differences among three samples of aroma components of Maillard reaction time of 8 h， 12 h，and 20 h，and no significant difference among three samples of aroma components of Maillard reaction time between 16 h，and 12 h. By sensory evaluation，it showed that by flavoring into blank cigarette，the sample of aroma components of Maillard reaction time of 12 h was the best.