When doctors consider liquid pneumothorax, patients need to undergo X-ray examination, which is an important method to diagnose liquid pneumothorax. Most patients with pneumothorax have obvious pneumothorax line on chest X-ray, which can be seen as the boundary of lung tissues under compression in the form of convex arc-shaped thin line shadow, which is the boundary line of the junction of compressed lung tissues and gas and liquid in the pleural cavity, and the outer translucency can be increased, and the lung texture cannot be seen. The lung tissue is compressed in this line, and when there is a large amount of pneumothorax, the lung can retract toward the lung door, showing a round spherical shadow, and the heart and trachea are displaced to the healthy side. In the presence of massive pneumothorax or tension pneumothorax, mediastinal shift is seen. In the presence of a mediastinal emphysema, a transilluminated band is seen next to the mediastinum, and the fluid is at the lowest level of the pleural cavity, which is visible in the patient’s obvious air-fluid plane.