Bronchoscopy is a diagnostic and therapeutic means to enter the trachea and bronchus through the nasal cavity or oral cavity or pharynx to directly observe tracheal and bronchial lesions. In the past, rigid bronchoscope was used, but in recent years, fiber-optic bronchoscope is mainly used, which is slim, soft and bendable, easy to operate and less painful for patients, and can reach into the segment or sub-segment of bronchus with wide field of view and strong light guide, so that biopsy, brush examination or bronchoalveolar lavage can be performed under direct vision. At present, it is mainly used for the early diagnosis of bronchopulmonary cancer, and can also provide a basis for the diagnosis of diffuse lung lesions, in addition to determining the cause of hemoptysis and the site of bleeding. In addition to the great progress in the diagnosis of respiratory diseases, it is also widely used in the treatment: 1. Removal of foreign bodies: There are many kinds of foreign bodies in the airway, including metal, plants and animal bones. When the disease is critical, especially in children under 7 years old, it should be performed in the operating room under general anesthesia and with SaO2 monitoring only. 2.Removal of respiratory secretions. 3.Bronchoalveolar lavage therapy: such as lavage therapy for alveolar protein deposition or pneumoconiosis. 4.Treatment of tracheobronchial stenosis: Tracheal stenosis caused by endotracheal tumors or bronchial tuberculosis can be released by endotracheal freezing, electrocautery and laser, and placement of stents. 5.Treatment of severe emphysema by transbronchoscopic lung decompression. 6.Treatment of bronchopleural fistula and tracheoesophageal fistula . 7.Treatment of hemoptysis. With the improvement of bronchoscopic diagnosis and treatment technology, more tracheobronchial diseases can be diagnosed and treated through bronchoscopic technology.