CT manifestations of lung cancer are different according to the types of lung cancer, and the common ones include lung occupation, nodular foci in lung, obstructive pneumonia, obstructive emphysema, pulmonary atelectasis, etc. 1. CT of peripheral lung cancer often shows space-occupying foci or nodular foci around the lungs, which are usually irregular in shape, with burrs on the edges, and the foci can be single or multiple. 2. Central-type lung cancer usually has occupying foci located at the hilar area, due to the obstruction of bronchial tubes or lumen of trachea by the tumor, therefore, CT often shows obstructive pneumonia, atelectasis or emphysema, and so on. 3. Metastatic lung cancer usually shows multiple nodular lesions in the lungs, some of which are located in the periphery of the lungs, some of which are located near the lung doors, often accompanied by obstructive pneumonia and other manifestations. It is suggested that patients should seek medical treatment in time to avoid delaying the condition.