When a mouth ulcer bleeds, the primary treatment is to stop the bleeding. A local sterile cotton ball or sterile gauze can be used to stop the bleeding by compression, and if necessary, a powder of Yunnan Baiyao can be applied to the corresponding area to enhance the hemostatic effect. It is also recommended that the patient undergo blood tests to check for significant abnormalities in platelets and coagulation in the patient’s blood count. Patients should be asked if they have a history of hematologic problems or if they have a history of hypertension, which could potentially affect local bleeding. Finally, it should also be noted that, in general, regular recurrent mouth ulcers do not bleed. With recurrent mouth ulcers, most of the clinical manifestations are mainly yellow ulcerated surfaces and more intense pain. Once a bleeding ulcer appears clinically, the patient must be extremely vigilant, and it is likely to be a cancerous ulcer. It is necessary to go to a professional stomatology department as soon as possible and consider a pathological biopsy of the ulcer for the next treatment of the disease.