Diagnostic applications of bronchoscopy: 1. diagnosis of lung cancer; 2. diagnosis of causes of hemoptysis; 3. diagnosis of pulmonary tuberculosis; 4. trans-fiber bronchoscopic lung biopsy (TBLB); 5. collection of respiratory secretions for pathogenic bacteria examination; 6. bronchoalveolar lavage (BAL) technique; 7. bronchography; 8. dynamic observation after disease treatment; 9. diagnosis of tracheal softening, etc. Bronchoscopy in treatment: 1, bronchoscopy-mediated tracheal intubation; 2, removal of foreign bodies in the trachea and bronchi; 3, bronchoscopic treatment of hemoptysis; 4, treatment of obstructive pulmonary atelectasis; 5, bronchoalveolar lavage or flushing treatment via bronchoscopy; 6, treatment of airway masses (freezing, high frequency, argon knife, etc.); 7, treatment of airway stenosis (balloon dilation, airway stent placement etc.).