Pneumothorax is the accumulation of air in the chest cavity. The formation of pneumothorax is mostly caused by the rupture of lung tissue, trachea, bronchus and esophagus and the entry of air into the pleural cavity. Pneumothorax can be divided into closed pneumothorax, open pneumothorax and tension pneumothorax. The pneumothorax mentioned here refers to closed pneumothorax. The intrathoracic pressure of closed pneumothorax is still lower than the atmospheric pressure, and a small amount of pneumothorax can be treated without surgery, and most of them can be absorbed on their own within 1-2 weeks, usually after oxygenation. However, a large amount of pneumothorax still requires surgical treatment by performing pleural puncture to extract the accumulated air or closed chest drainage to promote early lung reopening. For open pneumothorax and tension pneumothorax, surgical treatment is necessary because open pneumothorax and tension pneumothorax are life-threatening at any time. An open pneumothorax needs to be converted into a closed pneumothorax. Tension pneumothorax requires emergency coarse needle puncture with an external one-way valve device.