For known lung nodules, inflammation, etc., in order to clarify their nature, bronchoscopy is more accurate than CT. However, both have their own advantages and disadvantages. Bronchoscopy can observe the localization of the large airways, such as taking materials for pathology, to clarify the nature of the lesion, while CT can observe the abnormal changes in the whole chest, but can only have an image, and is not in direct contact with the lesion. Bronchoscopy is mainly used to assess the presence of lesions in the large airways, as well as through the bronchoscope to take a biopsy or retention of lavage fluid, to further clarify the nature of lung lesions, such as whether it is a tumor. It is more accurate in defining the nature of the disease. Chest CT is mainly used to evaluate the presence of lung lesions, such as pneumonia, emphysema, lung nodules or masses. In clinical practice, bronchoscopy and chest CT have their own advantages and complement each other. For many lung diseases, it may be necessary to do the above two tests at the same time to further determine the condition and target treatment. Therefore, in the clinic, those who suspect lung lesions need to consult a doctor in time, and choose the examination method under the guidance of the doctor reasonably.