Mouth ulcers can be properly supplemented with vitamin C, B vitamins, especially vitamin B2, etc. may be helpful. Mouth ulcers have many causes, including traumatic mouth ulcers, recurrent mouth ulcers, etc., but also with the body’s autoimmune function abnormalities, infections, suffering from underlying diseases, neurological, psychiatric factors, lack of vitamins and trace elements and so on have a certain relationship. Specifically can do vitamin and trace element blood test, targeted supplementation, the effect may be better. In addition, in addition to vitamin supplementation, we should also look for possible triggers, such as suffering from underlying diseases to be ruled out, including leukemia, lupus erythematosus and other immune-related diseases. Adjusting a good lifestyle to maintain a good immune status, and using medications such as topical antibacterial, anti-inflammatory, pain relieving, and ulcer healing medications, along with B-vitamins or vitamin C internally, can achieve a better therapeutic effect.