If a patient has an unexplained cough or other discomfort, the respiratory physician will request a chest X-ray first and then further CT chest examination if necessary. If the above tests still cannot make a definite diagnosis, especially if lung cancer is not excluded, the patient will definitely be asked to further improve the bronchoscopy. Moreover, at this time, this examination is especially important and necessary. Firstly, bronchoscopy is an important diagnostic tool to obtain a definite diagnosis of the disease. Secondly, through bronchoscopy, we can clarify whether there is any abnormality in the airway and the visual manifestation of the lesion to obtain the diagnosis directly. There was once a patient with a long-term irritating dry cough and a high suspicion of lung cancer on imaging, but the bronchoscopy clearly showed granulomatous stenosis, and a bony foreign body was found to fill the granulation. The patient had a history of choking and accidental ingestion of ribs six months ago, and since then, he had coughing and coughing, so he was considered to be a misunderstanding of ribs. Thirdly, even for some patients with peripheral lung cancer, it is still necessary to complete bronchoscopy by other means, such as CT-guided percutaneous lung aspiration biopsy, because it can help in the staging of lung cancer and the selection of surgical procedure, such as whether the trachea and bullae are invaded, whether the airway is narrowed and its degree, etc. Finally, for patients with combined obstructive pneumonia, bronchoscopy can also assist in lavage and drainage of sputum to alleviate symptoms, etc. Therefore, for patients suspected of having lung cancer, bronchoscopy is really necessary, so do not choke on it and miss the opportunity of early diagnosis.