Radiation-induced oral mucositis is the most common complication of radiotherapy for head and neck neoplasms. The relevant symptoms include oral pain dysphagia decreased diet intake and secondary infection which can lead to the interruption of treatment and even affect the clinical efficacy and quality of life. But so far there has been no effective treatment for the clinical management of radiation-induced oral mucositis and the treatment of patients with prevention pain and nutrition is mainly supported by treatment. In recent years glutamine as a kind of immunonutrient substance has become a research hotspot in the prevention of radiation-induced oral mucositis and has been mentioned in the guidelines of various countries which is currently in a stage of strong consensus but absence of abundant evidence. In terms of Nutriology glutamine is a non-essential amino acid and the most abundant free amino acid in the human body. In normal functioning the liver and skeletal muscle are the major organs that synthesize and store glutamine. While the main sites of glutamine consumption are brain tissue mucosa immune cells etc. Cancer patients are in a state of high catabolism of nutrients with an increased demand for glutamine but a decreased synthesis. Glutamine can not be timely replenished to the mucosa and immune cells which may have a negative impact on the prevention and treatment of radiation-induced oral mucositis. Based on current researches on radiotherapy—induced mucosal injury and the repair of glutamine on wound healing pathophysiology the mechanism of glutamine clinical research and application for radiotherapy—induced mucosal injury were reviewed aiming to provide references for clinical practice.