The upper leaf of K326 was used as test material, and subjected to curing by an electric heating flue–cured tobacco oven. The tobacco leaves were treated by dehydration (15%–20%) during the early yellowing stage (0–20 h) and the middle yellowing stage (20–44 h) to study the changes of moisture content, starch metabolism, cell wall material and physical properties of tobacco leaves. The results showed that the drying rate of tobacco leaves with dehydration decreased 30%–45% compared to the control. The level of amylase activity in tobacco leaves with dehydration at yellowing early stage was higher, and starch content in these tobacco leaves decreased 31% and cellulose content decreased 30% compared with the control treatment. While, there was no significant difference between the treatment of tobacco leaves with dehydration in the middle yellowing stage and control treatment. Horizontal shrinkage, vertical shrinkage, horizontal rolling index and vertical rolling index of flue–cured tobacco leaves with dehydration in the yellowing early stage were significantly larger compared to the control treatment. In addition, the equilibrium moisture content, tension and filling value of flue–cured tobacco leaves with dehydration in the yellowing early stage were better than those of the control treatment.