Always recurring mouth ulcers after quitting smoking may be caused by mental factors such as tension and anxiety after quitting smoking as well as changes in the environment of the oral mucosa, which can be treated with psychotherapy and topical medication. 1. Psychotherapy: after quitting smoking, there may be tension, anxiety, irritability and other emotions, which have a certain role in promoting the occurrence of oral ulcers, and can be relieved by appropriate psychotherapy to prolong the recurrence of oral ulcers. 2. Local medication: the environment in which the oral mucosa is located changes after smoking cessation, which may lead to the occurrence of oral ulcers, which can be treated by local use of drugs to promote healing, such as recombinant human epidermal growth factor gel or solution, in order to promote the healing of ulcers. Medications should be used under medical supervision. It is recommended to visit a regular healthcare facility to receive professional treatment.