Children’s mouth ulcers need to improve immunity and painful mucosal affected areas for topical medication for pain relief. The common cause of mouth ulcers in children is low immunity. When you have a cold or a fever, your body’s resistance decreases and mouth ulcers are easily triggered. Viral infections or bacterial infections can also cause ulcers, so you should do physical exercise to strengthen your resistance. You should eat more vegetables and fruits, such as apples, pears or oranges, to replenish vitamins, especially vitamin B and vitamin C. Pay attention to the nutritional balance of the diet, and pay attention to iron supplementation to avoid iron deficiency in the mucous membrane to increase brittleness and induce mouth ulcers in children. Pay attention to improving immunity, you can also take the oral drug transfer factor, or intramuscular injection of transfer factor. If children’s mouth ulcers are caused by external traumatic factors, such as the residual wall due to uneven tooth wear, sharp tooth tips scrape the mucous membrane ulcers, need to be adjusted to the corresponding grinding. For painful mouth ulcers in children, local anesthetic medications can be used to cauterize the pain and promote healing of the mucosa, and iodine glycerin can be applied to the affected area to relieve pain. Children’s mouth ulcers should be supplemented with vitamins to enhance nutrition and immunity, and local cauterization of the affected area to relieve pain.