Recurrent mouth ulcers have a complex etiology, which may be related to the body’s low immunity, oral flora imbalance and other factors, and can be controlled by medication and other means. 1. Recurrent mouth ulcers, clinically known as recurrent mouth ulcers or recurrent aphthous ulcers. The etiology is still unclear and complex, and may be related to the body in a subhealthy state of low immunity, oral colonization of bacterial flora imbalance, iron, zinc and other trace element deficiencies, oral mucosa local microcirculation disorders and other factors. 2. Mouth ulcers occur in the lips, tongue, cheeks and other places of the oral mucosa, the disease has a certain self-limiting. Severe recurrent oral ulcers can be intervened with medications, common medications include compound chlorhexidine gargle, mucosal wound application of montelukast, group aluminum thiosulphate tablets, metronidazole tablets, vitamin C, vitamin B2 and so on. The above drugs need to be used under the guidance of clinicians; the occurrence of recurrent mouth ulcers, it is recommended to visit the hospital in a timely manner.