The invention belongs to the technical field of tobacco planting and particularly relates to a compound for inhibiting tobacco buds and improving potassium in tobacco and an application method thereof. The compound comprises, by mass, 0 .005 to 0.01% of sodium alpha-naphthylate, 0.001 to 0.005% of sodium nitrophenolate, 0.005% to 0.01% of maleic hydrazide potassium salt, 0.01 to 0.05% of potassium magnesium sulfate, 0.1 to 0.25% of potassium dihydrogen phosphate, 0.001 to 0.005% of sodium salicylate and the balance of water. The application method comprises a spraying method and an injection instillation method. When the compound is used for spraying to tobacco leaves, an alkyl glucoside component having a mass fraction of 0.1 to 0.5% should also be used. The invention also provides the multi-effect compound which gets less external environment restriction, can effectively regulate and control the generation of tobacco axillary buds after topping, can increase the potassium content of the tobacco leaves and can enhance the quality of the tobacco. The compound is environmentally friendly, is poisonless and harmless, has no pesticide residues, is easy to use and has good comprehensive effects.