It is possible for lung carcinoma in situ to recur more than three years after surgery, and it is impossible to generalize due to the different conditions of individual patients. Lung carcinoma in situ refers to primary malignant tumors of the lungs occurring in the mucosa or glands of trachea, bronchus without metastasis, as well as carcinoma in situ with a diameter of less than 1cm. After surgical treatment, the prognosis of patients with lung carcinoma in situ is generally better, and they can also cooperate with radiotherapy and chemotherapy after surgery, and their chances of recurrence after three years are smaller, but still possible. After surgery, patients with lung carcinoma in situ are also recommended to take their own conditions into account and follow the doctor’s instructions for regular review, so as to know the recovery of the disease and whether the tumor recurs. Meanwhile, they should develop good living habits, quit smoking and drinking, and avoid passive smoking. Appropriate exercises, such as slow walking, playing Tai Chi, breathing exercises, qigong, etc., can be taken when the body allows, and avoid going to crowded places. Patients with lung carcinoma in situ need to ensure sufficient rest time in daily life, and do not overwork, so as not to damage their health.