To improve the stability of tobacco leaf quality, the nicotine, total sugar content in Gold Enleaf brand tobacco leaves before and after threshing and re-drying(vacuum moisture regaining, spreading leaf and untie bundle, first-moistening, second-moistening, stem-leaf separation, leaf blending and storage, re-drying) were determined and the effects of each process on the stability of sugar-nicotine ratio of tobacco leaves were analyzed. The results showed that ①after the threshing and re-dying process, the nicotine and total sugar content in tobacco leaves were decreased, nicotine content decreased by 9.50% with its coefficient of variation decreased from 10.95% to 2.75%, sugar content decreased by 9.43% with its variation coefficient decreased from 7.42% to 2.80%. Contents differences of sugar and nicotine in tobacco leaves before and after the threshing and re-dying process were extremely significant (P<0.01). ②The leaf storage process has the greatest contribution to the stability of nicotine and sugar-nicotine ratio, while the stem and leaf separation process contributes the most to the stability of total sugar content. ③The variation coefficient of sugar-nicotine ratio of tobacco leaves after the threshing and re-drying process was reduced from 16.87% to 4.15%. The vacuum moisture regaining process has a great influence on the reduction of the ratio of sugar to nicotine. The leaf storage process has a great influence on the increase of the ratio of sugar to nicotine, and the sugar-nicotine ratios before and after the vacuum moisture regaining and the leaf storage process both showed extremely significant differences.