The invention provides a segmented comprehensive utilization method for tobacco stems and relates to a method for comprehensively utilizing tobacco stem resources through segmented baking of the tobacco stems left after tobacco harvesting. According to the method, each tobacco stem is uniformly divided into five parts including an upper part, a middle-upper part, a middle part, a middle-lower part and a lower part; the upper part, the middle-upper part, the middle part and the middle-lower part are baked according to baking parameters of tobacco leaves in positions corresponding to the parts, and the baking time is 3-4 times that for baking the tobacco leaves; tobacco stem fibers are extracted from the baked tobacco stems at the upper part and the middle-upper part and used for preparing tobacco sheets; the baked tobacco stems at the middle part and the middle-lower part are preheated, dried, carbonized and activated for preparing activated carbon; the tobacco stem at the lower part is chopped and coordinates with fermentation auxiliaries, the mixture is fermented and thoroughly decomposed to serve as fertilizer for planting tobacco next year. The segmented comprehensive utilization method for the tobacco stems has the advantages that the utilization rate of each part of each whole tobacco stem can be optimized greatly, waste is reduced, and the tobacco stem baking process is relatively reasonable.