If there is an abnormality in the CT examination result, tracheoscopy may be performed to clarify the nature of lung lesions that cannot be diagnosed by CT; if the CT examination result is normal, tracheoscopy may be performed to look for the cause of unexplained symptoms such as hemoptysis. CT examination is only able to observe whether there are intrapulmonary lesions, such as lung nodules, lung occupations, etc., from the imaging, and it is not possible to clarify the nature of nodules and occupations directly through the image, and it is necessary to take tissue biopsy through tracheoscopy for diagnosis. Secondly, for lung shadows that are ineffective in repeated anti-infections, the nature of the disease can be clarified and diagnosis can be helped by bronchoscopy with alveolar lavage or tissue biopsy. In addition, for unexplained hemoptysis and other diseases with normal CT, the etiology can be explored through bronchoscopy to clarify the presence of bronchial tuberculosis, bronchial tumors, and rupture of bronchial mucosal capillaries. Bronchoscopy can not only obtain local tissue specimens to clarify the nature of the disease, but also has a therapeutic effect by directly performing endobronchial tumor resection under bronchoscopy and removing mucous secretions from the tracheobronchial tubes. Therefore, if necessary, bronchoscopy should be performed on medical advice.