Mouth ulcers can be caused by consuming too much spicy and stimulating food, fungal infections, systemic lupus erythematosus, etc. They can be treated by drinking more water, consuming less spicy and stimulating food, and using drugs such as clotrimazole and hydroxychloroquine. 1. Excessive consumption of spicy and stimulating food: avoid spicy and stimulating food, drink more water, regular work and rest, appropriate exercise, balanced diet, and eat more vitamin-rich vegetables and fruits. 2. Fungal infection: oral ulcers caused by fungal infection can be gargled with sodium bicarbonate solution or mycotoxin suspension, which can alleviate the uncomfortable symptoms; or take antifungal drugs such as clotrimazole and amphotericin B according to doctor’s advice. 3. Systemic lupus erythematosus: systemic lupus erythematosus can also lead to chronic mouth ulcers, you can follow the doctor’s instructions to use prednisone, hydroxychloroquine, thalidomide and other drugs to control and inhibit inflammation and autoimmune response, while paying attention to oral hygiene, avoid spicy and stimulating food. Long mouth ulcers after their own conditioning has not been relieved should go to the hospital in a timely manner to improve the examination to identify the cause of the disease and then targeted treatment and treatment, the use of drugs need to comply with the doctor’s instructions.