Using the tobacco cultivar Yunyan87 as the material, we designed 3 treatments involved T1(10 leaf-aged tobacco seedlings delayed transplanting, 136-cell seedling tray for floating seedling cultivation, with the seedling substrate enriched with “Miaoqiangzhuang” microbial fertilizer at 200 g/kg, and adding 30 kg/hm2 of “Genjingkang” microbial agent mixed evenly with the base fertilizer and applied in strips), T2(8 leaf-aged tobacco seedlings delayed transplanting, 200-cell seedling tray for floating seedling cultivation, with the seedling substrate enriched with “Miaoqiangzhuang” microbial fertilizer at 200 g/kg, and adding 30 kg/hm2 of “Genjingkang” microbial agent mixed evenly with the base fertilizer and applied in strips), and CK(200-cell seedling tray for floating seedling cultivation, no adding of “Miaoqiangzhuang” microbial fertilizer to the substrate, transplanting at 6-leaf stage, and no adding of “Genjingkang” microbial agent to the base fertilizer) to study the effects of different long-aged tobacco seedlings delayed transplanting on the economic traits and quality of flue-cured tobacco. The results indicate that T1 treatment can increase tobacco yield, economic value and top-grade leaf percentage, and can improve physical properties of leaves, enhance availability of chemical constituents in leaves and evaluate smoking quality. Compared with CK, T1 treatment increased top-grade leaf percentage, average price, yield, and economic value by 8.02%, 2.05%, 4.41%, and 6.58%, respectively. The appearance quality index for B2F, C3F, and X2F grades increased by 9.67%, 4.05%, and 9.67% respectively; physical property index for B2F and C3F grades increased by 0.85% and 6.38% respectively; chemical constituent availability index for B2F, C3F, and X2F grades increased by 1.2%, 20.85%, and 0.83% respectively; smoking quality index for B2F and C3F grades increased by 6.87% and 4.92% respectively; quality index for B2F, C3F, and X2F grades increased by 4.83%, 9.19%, and 1.84% respectively.