When air comes back after pneumothorax aspiration, it is considered that it may be caused by recurrence of pneumothorax or the rupture that formed the pneumothorax is not completely closed, and the gas spills back into the pleural cavity. Thoracentesis aspiration, commonly used in closed pneumothorax, is usually spontaneous pneumothorax, without the effect of trauma, the surface of the lungs or the pleura of the visceral layer rupture, creating a breach, and the air in the lungs enters the pleural cavity. Compression of the lung tissue and irritation of the pleura produce symptoms such as chest pain and dyspnea. When the gas in the chest cavity is extracted and then there is new gas, it is considered that the rupture of the lung may not be completely healed or a new gap reoccurs, and the air spills into the pleural cavity again, forming a pneumothorax. Treatment can be another thoracocentesis to extract air, and if necessary, closed thoracic drainage for continuous drainage of persistent intrathoracic air accumulation. Pneumothorax pumping again after the air, it is recommended to seek timely medical treatment, under the guidance of a professional doctor, standardized treatment.