Remnant lung resection for lung cancer refers to a lung lobectomy performed on one side of the lung because of a previous diagnosis of lung cancer, and then a new mass is found in the remaining lung on the same side during a review, and the remaining lung is surgically removed again. This procedure is called residual lung resection for lung cancer. It is equivalent to having two surgeries on one lung at different times. Such an operation is more difficult, and after the first operation, there will be atresia adhesions in the pleural cavity, disorganization of the hilar structures, and very difficult dissection of the pulmonary vessels. Many doctors are not interested in this type of surgery, which is very complicated to perform. In addition to concerns about the surgical technique, there is also a lack of adequate research and theoretical support about how much patients can gain from re-operation. However, if there are no other metastases as determined by systemic examination after recurrence and the body is able to tolerate reoperation, the results of residual pneumonectomy are still good. As long as radical treatment is possible, surgery is still the most effective treatment option.