The invention discloses a traditional Chinese medicine preparation for treating chronic periodontitis. Traditional Chinese medicine believes that gum inflammation, bleeding, redness, pain and bad breath are mostly caused by steaming from stomach fire, deficiency of kidney yin, and external invasion of fiery heat and evil poison. For this reason, the present invention selects Chinese medicine yellow-legged chicken, Xuanjingshi, Dendrobium, Anemarrhena, Huangcipi, Phellodendron, Horsetail, Radix Notoginseng, Radix Paeoniae Rubra, Purple Pearl Leaf, Indian Linden bark, Palladium minor, Glycyrrhiza licorice, by the traditional preparation method of our hospital's preparation room, decocted twice in water, combined the filtrate of the two times for oral administration, added the remaining medicinal residues to decoct in thick water, and filtered the medicinal solution for gargling. Through clinical trials, the total effective rate reaches 95.6%, which is obviously better than that of the control group.