The appearance of oral ulcers after radiotherapy is one of the side effects of radiotherapy, because radiotherapy is the most serious damage to mucous membranes, especially the oral mucosa. The oral mucosa is initially peeling, then moist, and then ulcers appear in severe cases, which is related to radiotherapy. At the same time, the oral ulcers are related to the dose of radiotherapy. At the beginning, the dose of radiotherapy is small, and the chances of oral ulcers and oral damage and mucosal damage are small, and the patient can tolerate them. The treatment taken is mainly to terminate radiotherapy first during radiotherapy, while taking symptomatic treatment, symptomatic treatment generally takes mucosal repair protective agent, mainly can use rehabilitation new liquid and other drugs gargle, at the same time, if there is infection, but also take antibiotics anti-inflammatory treatment.