The traditional single-lumen endotracheal intubation cannot ensure the airway is unobstructed due to the jelly or block of the gushing blood. The airway is completely blocked and the airway cannot be guaranteed. The double-lumen endotracheal intubation can provide a smooth airway and ensure adequate ventilation. The amount can also be used to block and treat the bleeding side, which can fully isolate the two lungs to achieve one-lung ventilation, quickly attract blood and clots in the airway, keep the respiratory tract open, and quickly correct hypoxemia; and ensure effective minutes ventilation, correct respiratory failure, and buy valuable time for the treatment of the primary disease; when the bleeding site is unclear, the bleeding site can be determined by suction through a suction tube or by fiberoptic bronchoscopy after double-lumen bronchial intubation. Provide basis for pulmonary vascular intervention and surgical procedures.