Chemotherapy is the main treatment for lung cancer, and more than 90% of lung cancers need to receive chemotherapy treatment. The efficacy of chemotherapy on small cell lung cancer is more certain no matter in early or late stage, and even about 1% of early stage small cell lung cancer is cured by chemotherapy. Chemotherapy is also the main treatment for non-small cell lung cancer, and the tumor remission rate of chemotherapy for non-small cell lung cancer is 40% to 50%. Chemotherapy generally cannot cure non-small cell lung cancer, but can only prolong the patient’s survival and improve the quality of life. 2.Radiation therapy has the best effect on small cell lung cancer, followed by squamous cell carcinoma and the worst adenocarcinoma. The radiation field of lung cancer should include the primary focus and mediastinal area of lymph node metastasis. It should be supplemented with drug therapy. Squamous cell carcinoma has moderate sensitivity to radiation, and the lesion is mainly locally invasive and metastases relatively slowly, so it is mostly treated with radical treatment. Adenocarcinoma has poor sensitivity to radiation and is easily metastasized by blood, so it is less often treated by radiation alone. 3.Surgical treatment Surgical treatment is the first and main treatment method of lung cancer, and the only treatment method that can cure lung cancer. The objectives of surgical treatment for lung cancer are: (1) complete removal of primary lesions and metastatic lymph nodes to achieve clinical cure; (2) removal of most of the tumor to create favorable conditions for other treatments, i.e., subtotal surgery; (3) subtotal surgery: suitable for a small number of patients, such as refractory pleural cavity and pericardial effusion, which can be cured or relieved by removing the pleural and pericardial implantation nodes and removing part of the pericardium and pleura clinical symptoms caused by pericardial and pleural cavity effusion, prolong life or improve quality of life. Decompression surgery requires both local and systemic chemotherapy. Surgical treatment often requires preoperative or postoperative adjuvant chemotherapy and radiotherapy to improve the cure rate of surgery and patient survival. The five-year survival rate of lung cancer surgical treatment is 30%-44%; the mortality rate of surgical treatment is 1%-2%. 4.Treatment of recurrent lung cancer Recurrent lung cancer includes the recurrence of local residual cancer after surgery and the new occurrence of second primary lung cancer in the lung. For recurrence of residual cancer of bronchial stump, re-operation should be pursued and bronchial sleeve molding should be performed to remove the residual cancer. For the second primary lung cancer occurring after complete lung cancer resection, as long as the lung cancer is suitable for surgical treatment, the patient’s visceral function can tolerate reoperative treatment, and there are no problems in surgical technique, reoperation to remove the recurrent lung cancer should be considered.