The invention discloses a traditional Chinese medicine preparation for treating periodontitis. The traditional Chinese medicine preparation for treating periodontitis is composed of the following medicinal raw materials: 3-8g of astragalus membranaceus, 3-8g of asarum, 3-8g of cinnabar, 3-8g of borneol, 2-4g of borax, 1.5-2.5g of realgar, 2-4g of radices trichosanthis, 1.5-2.5g of camphor, 2-4g of alumen, 1.5-2.5g of indigo naturalis and 30-60g of aloe. A preparation method comprises the following steps of: preparing astragalus membranaceus, asarum, cinnabar, borneol, borax, realgar, radices trichosanthis, camphor, alumen and indigo naturalis, mixing and uniformly grinding, then adding aloe, uniformly grinding, and blending into paste, namely the traditional Chinese medicine preparation. During treatment, the traditional Chinese medicine preparation for treating periodontitis is injected to the part with periodontitis by an injector or applied to the surface of the part with periodontitis by a cotton swab, applied once a day, one week for a treatment course, and periodontitis can be generally cured within 2-3 treatment courses. The traditional Chinese medicine preparation for treating periodontitis disclosed by the invention is capable of rapidly reducing the surface with periodontitis, reducing periodontitis exudation, relieving pain symptom and obviously reducing disease course, and free of obvious toxic and side effects.