Mouth ulcers are usually recurrent mouth ulcers, traumatic ulcers, and cancerous ulcers. The general elimination methods include the use of tretinoin ointment, rehabilitation of new liquid, surgical treatment, etc. There is no fast one. 1. Recurrent oral ulcers: it is a common oral mucosal disease with recurrent and self-limiting characteristics, and the ulcer site is usually unbearable. Mainly with the abnormal immune function, genetic factors, psychoneurological factors, trace elements, vitamin deficiency and many other factors related to the commonly used drugs, including benzocaine gel pain relief, tretinoin ointment, and so on. 2. Traumatic ulcers: generally caused by hard food or sharp edges of residual roots and crowns piercing the mucous membrane, etc. Local anti-inflammatory and analgesic drugs can be used to promote healing, such as rehabilitation of new liquid. 3. Cancer ulcer: if the patient’s ulcer does not heal for a long time, the diagnosis can be confirmed by biopsy and surgical treatment. It is suggested that patients should take medication under the guidance of professional doctors and should not take medication privately to avoid adverse consequences.