Mouth ulcers that do not heal for one month in a row may not necessarily be cancerous, but may be recurrent mouth ulcers that require pathological examination to determine the possibility of malignant transformation. If the mouth ulcer does not heal in the same location for more than one month, it may be due to poor body resistance, such as malnutrition. In addition, the local presence of repaired dentures, regular biting of the oral mucosa in the same location, betel nut chewing habits, etc., may also produce ulcers that do not heal for a long time. Oral ulcers that do not heal for a long time, or hard ulcers, or ulcers like cauliflower, need to pay great attention to the possibility of malignant change, when found to exist malignant change, need to be promptly examined, according to the results of the examination targeted treatment. At the same time, pay attention to a light diet, less spicy and oily food and other stimulating food, can be supplemented with vitamin C fruits and vegetables, so that the ulcer as soon as possible to improve. And can effectively prevent the recurrence of mouth ulcers.