Vitamin C is generally not recommended to be applied directly to mouth ulcers. Vitamin C belongs to the acidic substances, if applied directly to the ulcer surface, will stimulate the ulcer to appear local pain discomfort, affecting the healing of the ulcer surface. Oral ulcers can choose to use ice boron powder or watermelon cream spray spray on the ulcer surface, you can also choose recombinant human epidermal growth factor gel, nourishing yin sheng muscle powder, rehabilitation of new liquid and other drugs, in order to promote the healing of ulcers. Usually eat a light diet, do not eat spicy stimulating food, eat more fresh fruits and vegetables, appropriate outdoor exercise, can reduce the occurrence of mouth ulcers. Once the mouth ulcers, do not blindly self-medication, it is best to go to the hospital, under the advice of a professional physician to choose reasonable drugs to promote ulcer healing.