1.Brush carefully: brush your teeth comprehensively with a soft-bristled toothbrush; have frequent oral examinations and ask your dentist to treat bad teeth and repair damaged dentures in a timely manner. 2.Keep the oral cavity clean frequently, oral cleaning once every six months to a year. 3. Observe and record which foods are likely to trigger mouth ulcers and avoid eating less of such foods. 4. Pay attention to chew and swallow slowly. 5.Increase the intake of fruits and vegetables in order to replenish multivitamins and minerals. 6.Avoid eating ground foods such as minced bread, corn or potato chips, smoke less, drink less, eat less acidic foods such as citrus, tomatoes or nuts, eat less spicy or salty foods, avoid hard, too hot foods and chewing gum