In this paper, the effects of alkaline slag, oyster powder and lime on acid tobacco soil acidity, flue-cured tobacco yield and quality were investigated through field experiments. The results show that all amendments effectively promote soil pH, reduce the contents of exchangeable acidity and soluble Al, and increase soil exchangeable base cations. Alkaline slag has the best effect on soil acidity, which increases soil pH by 0.38 units, decreases exchangeable acid and soluble Al by 90.9% and 39.8%, and increases exchangeable Ca²⁺ and Mg²⁺ by 72.8% and 91.9%, respectively. With the improvement of soil properties, all three amendments promote the growth of flue-cured tobacco, and increase the yield and intrinsic quality of tobacco leaves. With the application of amendments, the yield of tobacco leaves is increased by 6.0%-9.5%, the proportion of top-grade tobacco leaves is increased by 4.0%-16.9%, the output value is increased by 11.7%-19.5%, and the net increase income is increased by 4 593.00- 9 270.30 yuan/hm². Alkaline slag presents the greatest improvement on tobacco yield and income, which is consistent with its effect on soil acidity. In addition, the application of amendments optimizes the chemical composition of flue-cured tobacco leaves, and among all the treatments, tobacco leaves treated with oyster powder has the best inherent quality. In conclusion, the use of alkaline slag to improve acid tobacco field presents a broad application prospect, however, more attentions should be paid to controlling Na and Cl contents in alkaline slag in practical application.