The invention discloses an aroma-increasing and humidity-preserving additive for cigarettes and a preparation method and application thereof. The additive contains a traditional Chinese medicine extract composition or a compound traditional Chinese medicine extract. The traditional Chinese medicine comprises epimedium, eclipta herb, coltsfoot flower, leonurus, dandelion and trichosanthes peels. The preparation method of the aroma-increasing and humidity-preserving additive comprises respectively using a solvent to extract and refine the epimedium, the eclipta herb, the coltsfoot flower, the leonurus, the dandelion and the trichosanthes peels and mixing the ingredients according to the proportion of 1-8:0.8-6:0.5-4:0.3-4:0.3-5:1 to prepare the aroma-increasing and humidity-preserving additive, or mixing the epimedium, the eclipta herb, the coltsfoot flower, the leonurus, the dandelion and the trichosanthes peels according to the proportion of 0.5-8:0.5-6:0.2-4:0.3-4:0.3-5:1 and then using the solvent to perform extraction and refining to prepare the aroma-increasing and humidity-preserving additive. The additive is added into tobacco shreds, cut stems and slices for cigarettes, and the adding proportion is 0.002-1%wt. After the additive is added into the tobacco shreds, the cut stems and the slices for the cigarettes, the moisture of the tobacco shreds can be maintained in the normal-temperature dry environment, the additive has good physical humidity-preserving effect and integrally improves the intrinsic quality of the cigarettes.