There are many examination methods for lung cancer, as follows: 1. Like other respiratory diseases, the main thing is lung imaging, CT is recommended. Low-dose CT can be used for screening, but to confirm lung cancer, low-dose CT is not recommended because its resolution is more limited. CT of the lung can visualize the location, size, and relationship of the tumor to the surrounding blood vessels, mediastinum, and airway. If the tumor invades the blood vessels, especially the superior vena cava, it is possible to do MRI to see the local vascular invasion. 2. A very important examination is bronchoscopy or percutaneous pulmonary puncture intervention means, because it is a very important way to obtain pathological biopsy information of the tumor. For peripheral lesions, percutaneous CT-guided or ultrasound-guided puncture is required. Because of the rapid development of bronchoscopic technology and the development of guidance technology, many peripheral nodules can be diagnosed by bronchoscopy, including mediastinal lymph nodes, which can also be biopsied under bronchoscopy. There are also some routine examinations, including blood tumor cells, tumor marker examination, routine biochemical examination of blood; 3. Systemic screening, including brain CT and MRI for brain metastasis, as well as routine screening of kidney and bone. Although it is more expensive, it is very useful for the overall assessment of the disease, including lymph node metastasis and the regression after treatment.