The invention relates to a traditional Chinese medicine composition for treating oral lichen planus. An orally taken medicine comprises the following raw materials: 10 to 20 parts of rehmanniae vaporata, 10 to 20 parts of raspberries, 10 to 20 parts of leonurus, 10 to 20 parts of astragalus membranaceus, 10 to 20 parts of rhizoma anemarrhenae, 10 to 20 parts of semen cuscutae, 10 to 20 parts of polygala tenuifolia, 10 to 20 parts of bighead atractylodes rhizomes, 10 to 20 parts of rhizoma cyperi, 10 to 20 parts of scutellaria baicalensis, 10 to 20 parts of glossy privet fruits, 10 to 20 parts of prepared fleece flower roots, 10 to 20 parts of eclipta alba, 10 to 20 parts of medlar, 10 to 20 parts of roots of common peony, 10 to 20 parts of radix ophiopogonis, 10 to 20 parts of herba epimedii, 10 to 20 parts of radix polygonati officinalis, 10 to 20 parts of roots of straight ladybell and 10 to 20 parts of oldenlandia diffusa. An external use medicine comprises the following raw materials: 10 to 20 parts of cutch, 10 to 20 parts of nightshades, 10 to 20 parts of fructus forsythiae, 10 to 20 parts of radix angelicae, 10 to 20 parts of mints, 10 to 20 parts of indigo naturalis, 10 to 20 parts of dandelions, 10 to 20 parts of borneols, 10 to 20 parts of golden cypresses and 10 to 20 parts of oldenlandia diffusa. The pathogenesis of the oral lichen planus is complex, so that therapeutic methods are different from each other, but the effect is undesirable. The research finds that the traditional Chinese medicine composition combined with the immunological therapy is excellent in curative effect in treating the OLP (Oral Lichen Planus), so that the traditional Chinese medicine composition is worthy of popularization and application. The whole formula primarily nourishes liver and kidney and secondarily sooths liver-qi stagnation and purges fire for removing toxin, tonification and purgation are performed in combination, and yin and yang are mutually aided, so that the essential qi in kidney is full, the liver, the spleen, the heart and the lung are moistened and nourished, and the symptom of oral mucosa is improved.