Oral ulcers, commonly known as mouth sores, are ulcerative diseases that occur in the oral mucosa. Clinically, recurrent oral ulcers are the most common, mostly found on the lips, cheeks, gums and other parts of the mouth, and are characterized by self-healing and recurrent attacks. Recurrent oral ulcers are a common type of oral mucosal damage, and patients may experience severe pain and burning sensation on the ulcerated surface, which may affect diet, speech, mental state and normal life in severe cases. Recurrent oral ulcers are mainly characterized by significant local pain, yellow pseudomembrane covering the ulcer surface, central depression, and congestion and redness of the surrounding mucosa.