Oral lichen planus is one of the most common diseases of the oral mucosa. There is no specific cure for oral lichen planus, and generally asymptomatic people do not need treatment and can be observed regularly. For those with severe disease and ulcers or erosions, local and systemic treatment can be used. The cause of oral lichen planus is unknown, but it is mainly related to autoimmune disorders, endocrine disorders, mental factors and systemic diseases. Because the cause of lichen planus is unknown, it is difficult to cure and eradicate, but after systematic treatment and regular checkups, the condition can be controlled. The treatment focuses on the following points: 1. Pay attention to the elimination of local irritants, such as tobacco, alcohol, dental calculus, residual roots, residual crowns, sharp tooth cusps, cavities or dental defects, bad restorations and dental filling materials, etc. 2.Actively treat systemic diseases, such as gastrointestinal diseases, hepatitis, diabetes, etc. If the occurrence of the damage is suspected to be related to the patient’s long-term use of a certain drug, it can be recommended to switch to other drugs. 3.If the damage is limited and asymptomatic, no medication may be used, only observation and follow-up. 4.For those with limited damage but symptoms, local medication is the mainstay. 5.For more serious damage, combined local and systemic drugs are used. 6.The systemic medication is mainly immunomodulatory treatment. 7. Pay attention to the control of secondary infections, especially fungal infections. 8.Strengthen psychological guidance and relieve mental stress, and suggest patients to have psychological counseling and treatment if necessary. 9.Follow up regularly to prevent cancer. If the disease is in remission, it should be reviewed once every 3-6 months, or once a year if it is stable.