Oral ulcers are a common disease that many people encounter. Those who have long-term, non-healing oral ulcers often worry about the possibility of oral cancer, causing them considerable concern. The factors contributing to the onset of oral ulcers include genetics, infection, immune responses, and local irritation from foreign bodies. A deficiency in nutrients is also a significant factor; deficiencies causing oral ulcers mainly include a lack of vitamin B2, folic acid, trace elements, zinc, iron, and other cases of poor nutrition. Therefore, it is advisable to consume more fruits and vegetables in the diet to supplement vitamins and sufficient nutrients, preventing the occurrence of oral ulcers.