Oral ulcers, also known as mouth sores, are a common disease occurring in the oral mucosa of patients, and their onset sites are commonly found in various parts of the inner lip, tongue margin, buccal mucosa, gums, soft palate and vestibular groove, with remarkable periodicity and recurrence. Usually, the five stages of oral ulcers are as follows: Stage I: there is a local bump, the edge of the ulcer is not clear, and the patient will feel foreign body sensation, such as itching; Stage II: the mucosa is locally red and swollen, and the edge of the ulcer site is gradually clear; Stage III: as the inflammation progresses, the center of the ulcer often appears as a white or yellow-green ulcer spot or ulcer surface, with a pseudomembrane covering the surface and a central depression, single or The patient feels pain, which is aggravated when eating and even affects swallowing; Stage 4: The oral ulcer is self-limiting and the inflammation recovers by self-absorption, or in heavy cases, after receiving inflammation control treatment, the pain is gradually reduced and the depressed surface of the ulcer is reduced and leveled off; Stage 5: The oral mucosa finally achieves complete healing and most of them do not leave traces. The recovery process of oral ulcer varies from person to person, some people can recover within 1 week, some people need more than 2 weeks, but generally 1-2 weeks can get a complete recovery. Daily attention should be paid to oral care, keep the oral cavity clean and hygienic, eat a light diet, replenish the nutrients needed by the body, avoid spicy food stimulation, avoid smoking and alcohol, etc. to enhance the immunity of the body and prevent the recurrence of mouth ulcers.