Mouth ulcers are largely related to personal physical quality, so it is unlikely to completely avoid their occurrence, but the incidence can still be reduced if the triggering factors are avoided as much as possible. Specific measures are: 1, pay attention to oral hygiene, avoid damage to the oral mucosa, avoid spicy food and local stimulation. 2, keep a relaxed mood, optimistic and cheerful, avoid things and anxious. 3.Ensure sufficient sleep time and avoid over fatigue. 4, pay attention to regularity of life and balanced nutrition, develop certain bowel habits to prevent constipation.