Children with mouth ulcers can eat more vitamin-rich foods such as apples, pears, persimmons, watermelon, peaches and apricots. Apples are vitamin-rich fruits that are ideal for treating mouth ulcers. Persimmons are also effective in preventing mouth ulcers, especially persimmon cream, which can be taken from persimmon cakes with boiling water or added to porridge. Watermelon is rich in vitamins and has the effect of quenching thirst, but it should not be eaten in excess, and it is easy to aggravate the symptoms of mouth ulcers when eaten in excess. Peach and apricot, peach and apricot are rich in vitamin B and other vitamins, for mouth ulcers have a better effect, but also should not eat more. In addition, eat less acidic food, such as citrus, tomatoes or nuts, eat less spicy or salty food, avoid eating hard, too hot food.