Using flue-cured tobacco cultivar Yunyan87 as the material, the effects of two topdressing modes (traditional topdressing and water-soluble topdressing) combined with root promoting agents(Dikangshian1, Youkangte and Puduoshoumoligen) on the accumulation of dry matter, nitrogen, phosphorus and potassium, and on fertilizer absorption efficiency and fertilizer production efficiency of flue-cured tobacco at different days after transplanting were studied. The results showed that the traditional topdressing mode was not conducive to the nitrogen removal of tobacco leaves, while the water-soluble topdressing mode could promote the yellowing and ripening of tobacco leaves. Water-soluble topdressing mode and root promoting agents and their interactions were beneficial to dry matter accumulation, and could improve nitrogen, phosphorus and potassium accumulation and distribution, and increase nutrient absorption efficiency and production benefit of flue-cured tobacco. The contribution rates of topdressing mode, root promoter and their interaction to dry matter accumulation were 37.64%, 41.35% and 21.01%, respectively; the contribution rates of topdressing mode, root promoter and their interaction to nitrogen accumulation were 34.14%, 33.78% and 32.08%, respectively; the contribution rates of topdressing mode, root promoter and their interaction to phosphorus accumulation were 34.41%, 33.47% and 32.12%, respectively; and the contribution rates of topdressing mode, root promoter and their interaction to potassium accumulation were 32.12%, 36.56% and 25.16%, respectively. In Hunan tobacco-rice rotation area, the application of water-soluble topdressing combined with the application of Dikangshian 1 and Youkangte can significantly promote the dry matter accumulation of flue-cured tobacco in early growth stage, significantly increase the accumulation of nitrogen and phosphorus, and effectively improve the fertilizer absorption efficiency and production efficiency.