The precautions for fiberoptic bronchoscopy are as follows: 1. Patients should fast for 4-6 hours before the examination, and it is generally recommended that patients should not eat after 10 pm if the examination is performed in the morning; 2. It is recommended that patients should do coagulation or routine blood tests before the examination, because patients with poor coagulation have certain risks when doing electronic bronchoscopy, which may lead to internal bleeding in the airway. It is recommended that patients with respiratory symptoms should bring along the corresponding examination data, such as chest X-ray or CT, before the examination, and electronic bronchoscopy will be done according to the patient’s lesion site. 5, need to be accompanied by family members, patients should not come alone to do the examination, because the examination process may produce discomfort, need to communicate with family members; 6, after doing the examination within 2 hours can not eat or drink, may choke, because when doing electronic bronchoscopy, will do anesthesia, may lead to airway is not completely closed, causing mis-aspiration state.