The pleural cavity consists of the wall layer of the pleura and the dirty layer, which are airtight potential cavities that do not contain air. Any cause that breaks the pleura and air enters the pleural cavity is called pneumothorax. Liquid pneumothorax refers to the accumulation of blood or tissue fluid in the pleural cavity, at which time the pressure in the pleural cavity increases, and even the negative pressure becomes positive pressure, so that the lungs are compressed and the venous blood flow back to the heart is obstructed, producing different degrees of lung and heart dysfunction. The lung without obvious lesions formed by the rupture of subpleural emphysema bubble is called idiopathic liquid pneumothorax; secondary to chronic obstructive pulmonary tuberculosis and other pleural and lung diseases is called secondary liquid pneumothorax. 1, traumatic liquid pneumothorax: a variety of common chest trauma, including sharp-edged stab wounds and gunshot penetrating wounds rib fracture end dislocation stab wounds lung, as well as diagnostic and therapeutic medical operations in the process of lung injury, such as acupuncture puncture lung biopsy, artificial pneumothorax, etc. 2, secondary liquid pneumothorax: for bronchopulmonary disease broken into the chest cavity to form a pneumothorax. Such as chronic bronchitis, pneumoconiosis bronchial asthma caused by obstructive pulmonary disorders, pulmonary interstitial fibrosis, cellular lung and bronchopulmonary cancer partially occluded airways produced by vesicular emphysema and pulmonary alveoli, as well as septic pneumonia near the pleura, pulmonary abscess tuberculous cavity, pulmonary fungal disease, congenital pulmonary cysts, etc. 3, idiopathic fluid pneumothorax: refers to the usual history of no respiratory disease, but there can be subpleural pulmonary alveoli, once rupture to form a pneumothorax is called idiopathic pneumothorax is mostly seen in lean, long-bodied male young adults. 4, chronic liquid pneumothorax: refers to the pneumothorax after 2 months without full reopening. The reasons for this are: absorption difficulties of the encapsulated liquid pneumothorax, not easy to heal the bronchial negotiation pleural fistula alveoli or congenital bronchial cysts formed by the pneumothorax, as well as the airway obstruction or atrophy of the lung connected with the pneumothorax covered with a thicker mechanized envelope to prevent lung reopening. 5, traumatic fluid pneumothorax: the accumulation of air in the pleural cavity is called pneumothorax. The incidence of traumatic pneumothorax accounts for about 15% to 50% in blunt injuries, and about 30% to 87.6% in penetrating injuries.