1.Chest X-ray: It is an important means to diagnose lung cancer and can detect lung shadows through fluoroscopy or frontal and lateral X-ray chest film. 2.CT of the chest: It can detect and clearly show the size, shape and cumulative extent of lesions in the hilum, lung and mediastinum at an earlier time, which can help to diagnose whether lung cancer can be removed. 3.Magnetic resonance imaging (MRI): to determine the extent of lung cancer invasion, stage and the possibility of surgical resection. Guo Gang, Department of Thoracic Surgery, Yunnan Cancer Hospital 4.Positron emission computed tomography (PET): It helps to identify benign and malignant tumors. 5.Sputum cell examination: through sputum examination, some lung cancer patients can be diagnosed and the histological type of lung cancer can be judged at the same time, but it takes 4 to 6 times of consecutive examinations to obtain the results. 6.Fiber bronchoscopy: It can obtain pathological diagnosis, which is helpful to determine the scope of lesions and clarify the surgical guidelines and methods. 7.Digital subtraction angiography: It can understand whether there is lymph node metastasis in the lung gate and the degree of tumor invasion of bronchial biscuits, and clarify whether there are specific lesions in the shadow of lung field. 8.Percutaneous lung aspiration biopsy: It is suitable for sputum cytology and bronchoscopy that cannot obtain positive results, peripheral masses with small intrapulmonary lesions and new peripheral pulmonary lesions, lesions with unclear growth history, multinodular lesions in the lungs, patients with incurable tendency, and lesions that do not require resection. 9.Mediastinoscopy: It is beneficial to the diagnosis of tumor and TNM staging. 10.Thoracoscopy: It is mainly used to determine the nature of pleural effusion or pleural mass. 11.Serum tumor marker test: to indirectly determine the existence of malignant lesions by detecting the unique substances secreted into the blood by the lesions.