Ulcers in the mouth should first be treated for systemic diseases, and it is important to regulate the mental state to reduce insomnia. If necessary, vitamin supplements such as ferrous sulfate, folic acid and or complex vitamin B and vitamin C can be used. In addition, it is recommended to use appropriate drugs to promote healing, commonly used are tretinoin ointment, and if the ulcer is deep and large you can choose prednisolone acetate suspension to use local closure, and can use laser echo or intraoral ultraviolet lamp to irradiate, these physical means to treat stubborn ulcers. And if there are ulcers in the mouth, if they are caused by a low immune system, the immune system should be regulated promptly. Commonly used drugs include levamisole and thymidine injection, which can improve the body’s resistance and avoid recurrent ulcers. You can also use the appropriate mouthwash, commonly used mouthwash are furacilin liquid or compound chlorhexidine rinse.