Oral lichen planus is a chronic non-infectious inflammatory disease of the skin mucosa and is one of the common diseases of the oral mucosa. The disease is mainly manifested by the appearance of pearly white streaks in the oral cavity on the cheeks, tongue, lips and gums, extending in all directions and forming different forms such as reticulation, dendrites, rings and plaques, and sometimes lesions such as congestion, blistering, erosion and atrophy can occur. Patients feel local roughness, irritation pain or spontaneous pain. It is a precancerous state, especially the long-term repeatedly unhealed vesicular or atrophic lesions, which should be paid enough attention. At present, the etiology of oral lichen planus is still unclear, immune factors and psychoneurological factors play a key role in the pathogenesis, and clinical observation shows that the disease often develops or worsens under emotional fluctuations, work or study stress. Chinese medicine believes that the occurrence of this disease is related to various factors such as internal injuries, external dampness and heat, internal disorders, and disharmony of qi and blood. The disease is located in the oral cavity, and the internal organs are mainly involved in the heart, liver, spleen, stomach and kidney. The pathological mechanism of damp-heat accumulation, Yin deficiency and heat, Qi stagnation and blood stasis, Qi and blood deficiency, resulting in heat and toxicity fumigation of skin couples, skin loss of moistening, local Qi and blood, and a series of mucosal pathological changes. Western medicine treatment is mainly summarized as follows: 1, glucocorticoids, such as prednisone tablets, dexamethasone tablets systemic treatment; tretinoin suspension, betamethasone suspension, fluocinolone ester, Ancinolone local treatment. 2.Immunosuppressants, mainly thalidomide, hydroxychloroquine sulfate and cyclosporine A mouthwash, 0.1% tacrolimus ointment or gargle, etc. 3.Immunomodulators, the optional drugs are levamisole, multi anti-methoxazole, polymyxin, transfer factor, BCG polysaccharide nucleic acid injection, thymidine injection, pidomod, etc. 4.Anti-microbial drugs are necessary adjuvant therapy drugs in OLP treatment. Amoxicillin, roxithromycin, tinidazole, fluconazole, tri-potassium di-citrate sodium bismuth, 0.2% chlorhexidine, Alec mouthwash, 2%-4% baking soda solution, diquantine chloramine oral tablets, acetylglucosamine oral tablets, etc. are used according to different situations. 5.Promote epithelial growth drugs goldin peptide gel, goldin peptide spray. The application of glucocorticoids and immunosuppressants is more effective in improving the lesions such as congestion and erosion, but the drugs have certain side effects and should not be used for a long time. Moreover, there is still a lack of special treatment methods and drugs, and it is difficult to heal the lesions, and there are more relapses after treatment. Chinese medicine is a combination of evidence-based and disease-based treatment, which can improve the immunity of the body by nourishing the yin and kidneys, tonifying the qi and blood, and regulating the yin and yang, so as to achieve the purpose of supporting the righteousness and eliminating the evil, strengthening the root and preventing recurrence. By clearing heat and detoxification, dispelling wind and dampness, activating blood circulation and removing blood stasis, etc. to improve and eliminate local lesions. Through years of clinical practice, we have summarized the experience of Chinese medical evidence-based treatment of flat moss medicine. 1, liver depression and qi stagnation evidence: adapted to early mild patients, or emotional fluctuations caused by the lesions. Treatment principle: dredge the liver and Qi, activate blood circulation and remove blood stasis. Commonly used drugs: Chai Hu 15g, Scutellaria baicalensis 10g, Yu Jin 10g, Bai Shao 10g, Dan Pi 10g, Dan Shen 10g, Safflower 10g, Huang Qi 15g, Xuan Shen 10g, Licorice 3g. 2. Spleen deficiency, dampness and heat evidence: suitable for those with prolonged illness, erosion and more exudation. Treatment principle: strengthen the spleen and dispel dampness, clear heat and detoxify. Commonly used drugs: Radix Codonopsis 10g, Poria 10g, Coix Coix 10g, Bryophyllum 10g, Houpa 10g, Salvia 10g, Plantago ovata 10g, Dandelion 10g, Bupleurum 10g, Astragalus 10g, Glycyrrhiza 3g. 3, heat toxin accumulation evidence: suitable for those with exacerbation period, vesicles, congestion and pain symptoms are more severe. Commonly used drugs: Scutellaria baicalensis 10g, Phellodendron cyperus 10g, Coix seed 10g, Scutellaria tulipifera 10g, Dandelion 10g, Danshen 10g, Safflower 10g, Astragalus 15g, Radix et Rhizoma Chaihu 10g, Glycyrrhiza glabra 5g. 4, Yin deficiency internal dryness evidence: adapted to the remission period, simple oral mucosal mottling. Treatment principle: nourishing Yin and nourishing Blood, invigorating Blood and eliminating spots. Commonly used drugs: 10g of raw earth, 10g of dangpi, 10g of angelica, 10g of wolfberry, 10g of xuan shen, 10g of danshen, 10g of safflower, 10g of white mossy bark, 15g of astragalus, 3g of licorice. In short, oral lichen planus is a chronic and prolonged disease, patients still need self-psychological adjustment, dietary regimen, avoid fishy, spicy and hairy things, pay attention to proper rest, do not The patient should not be in a hurry. Through the cooperation between doctors and patients, this disease can be treated and healed.