Autofluorescence bronchoscopy (AFB) is a new type of bronchoscopy developed by adding blue excitation light to ordinary white light bronchoscopy and using cellular autofluorescence and computerized image analysis technology. The autofluorescence of tissue cells is produced when irradiated by specific wavelengths of light, and the autofluorescence of diseased tissues is different from that of normal tissues; AFB examination detects mucosal lesions by distinguishing the difference in fluorescence between normal and abnormal mucosal tissues. Ordinary white light bronchoscopy relies entirely on the human eye to identify morphological changes, and early lesions are often undetectable. AFB can detect fine mucosal surface early lesions with a much higher diagnostic ability than ordinary white light bronchoscopy. The sensitivity of autofluorescence bronchoscopy for early localization and diagnosis of lung cancer is significantly better than that of ordinary white light bronchoscopy, which helps to improve the detection rate of early cancerous lesions, and the application of fluorescence bronchoscopy can help us to detect precancerous lesions early and assist in more accurate lung cancer staging. In recent years, with the aggravation of air pollution and the increasing number of smokers, the incidence of bronchopulmonary cancer has been increasing year by year. Since bronchopulmonary cancer has no obvious clinical symptoms in the early stage, many patients have progressed to the advanced stage of tumor when they present symptoms and seek medical treatment, losing the best time for treatment. At present, the only method to cure bronchial lung cancer is early resection, and for patients in the middle and late stages, it is mainly palliative chemotherapy and radiotherapy. Radiotherapy has more side effects on patients and it is difficult to eradicate malignant tumors. Therefore, early detection, early diagnosis and early treatment for bronchial lung cancer are very important. At present, for high-risk groups, such as long-term heavy smokers, long-term exposure to “second-hand smoke”, family history of tumor, and chronic cough patients who have not been cured, the main screening measures are chest X-ray or CT, sputum cytology, blood tumor markers and bronchoscopy. Among them, bronchoscopy is important for the diagnosis of bronchial lung cancer because it can directly see the inside of airway and take biopsy under the microscope. Years of medical research have found that human tissues contain specific fluorescent groups, which can emit brightly colored fluorescence after irradiation by certain wavelengths of light. Due to the difference of biochemical structure between tumor tissue and normal tissue, the fluorescence groups contained in them are different, resulting in different colors of fluorescence excitation. Electronic autofluorescence bronchoscopy makes use of this principle, allowing us to detect those early and potentially diseased tissues. The technique was first introduced in Europe, the United States and Japan, and numerous clinical studies have confirmed that autofluorescence significantly improves the early diagnosis of bronchopulmonary cancer, and that it is safe and economical because it does not require any preoperative contrast agent.