The invention discloses a traditional Chinese medicine preparation for treating periodontal diseases and a preparation method and belongs to the field of traditional Chinese medicines. The effective ingredients of the traditional Chinese medicine preparation are extracted from raw materials as follows: dahurian angelica roots, mint, cicada slough, roots of spiny raspberries, sweet-scented osmanthus, herbs of smallflower houndstongue, prismatomeris tetrandra, Chinese globeflower flowers, mulberry leaves, swertia bimaculata, simpleleaf shrub chastetree fruits, forbes wildginger herbs, roots and rhizomes of canton fairybells, coix seeds, twigs and leaves of pilular adina and Taiwan beautyberry leaves. The traditional Chinese medicine preparation is prepared from medicinal materials matched properly, accords with traditional Chinese medicine and modern medicinal and pharmacological theories, has the efficacy of eliminating swelling, relieving pain, eliminating pus, stopping bleeding, killing bacteria, eliminating inflammation, clearing heat and removing toxins, is convenient to take, has a good absorption effect, is free of adverse, toxin and side effects, has a great relieving and treatment effect on periodontal diseases as is shown in clinical experience, and is suitable for popularization and application in clinical treatment and nursing of the periodontal diseases.