The examination methods of lung cancer mainly include: 1. Chest CT examination: it is the main means to screen lung cancer. Low-dose spiral CT has lower radiation, which is less harmful to patients and can detect early lung cancer; 2. Pathology: if nodules appear in the lung, the type of nodules can be determined through fine needle aspiration, bronchoscopy or minimally invasive surgery; 3. Sputum examination: if there is blood in sputum and the amount of blood is large, sputum examination can be performed; 4. Other examinations: tumor markers, abdominal CT, head CT, bone scan and PET-CT.