The results of bronchoscopy can be categorized into clarifying the nature of lung mass or nodule, finding the source of suspected positive sputum exfoliative cells, and finding the cause of chronic cough and phlegm, etc. Different results can be obtained according to the different purposes of bronchoscopy. 1. Define the nature of lung mass shadow or nodule shadow: bronchoscopy obtains histopathological or cytopathological specimens through clamping, brushing and lavage, etc. to define the nature of lung mass shadow or nodule, and to locate and diagnose lung foci. If the patient has a chest imaging test suggestive of lung mass shadow, bronchoscopy can be used to clarify the nature. 2. Finding the source of suspicious positive sputum exfoliated cells: if the patient’s sputum cytology reveals cancer cells and there is no abnormality in the imaging examination, then bronchoscopy should be performed to observe the abnormal signs in the bronchial tubes (e.g. the lumen of the bronchial tubes is not smooth, the surface of the mucous membrane is rough, etc.), and then bronchoscopy specimen should be collected to find out the source of the sputum exfoliated cells. 3. Find the cause of chronic cough and sputum: If the patient has smoking, chronic bronchitis, tuberculosis, bronchial tuberculosis, airway foreign body and other diseases, feasible bronchoscopy under direct vision to observe the presence of purulent secretion, lumen of the new organisms or clamp pathological tissue for histological examination in order to find the cause of chronic cough and sputum. Bronchoscopy is an endoscopic examination, there are clear indications and contraindications, the patient should be under the guidance of the doctor to carry out standardized examination, such as the emergence of complications should be dealt with in a timely manner.