Laryngoscopy, including indirect laryngoscopy, electronic fiberoptic laryngoscopy, dynamic laryngoscopy and strobe laryngoscopy, etc., can observe the laryngeal structure and function, and make targeted examination for laryngeal trauma, chronic laryngitis, laryngeal cancer and other diseases according to the open condition of laryngeal cavity. 1. Laryngeal trauma: including closed laryngeal trauma, laryngeal intubation injury and so on. When there is closed laryngeal trauma, indirect laryngoscopy or electronic fiberoptic laryngoscopy can see laryngeal mucous membrane swelling, vocal fold deformation, vocal cord rupture and other symptoms. When laryngeal cannula injury occurs, laryngoscopy can see fixed or restricted movement of the arytenoid cartilage on the affected side during vocalization, accompanied by mucosal swelling and incomplete closure of the vocal folds. 2. Chronic laryngitis: if it is chronic simple laryngitis, laryngoscopy can see diffuse congestion of pharyngeal mucosa, and the vocal folds change from white to pink and the edges become blunt; if it is hypertrophic laryngitis, indirect laryngoscopy can not see the anterior part of the vocal folds, which can not open the vocal folds completely; if it is atrophic laryngitis, laryngoscopy can see the pharyngeal mucosa become thin and dry, and the surface of the surface of the laryngeal mucosa is formed as a crust in the severe cases. 3. Laryngeal cancer: In laryngoscopy, the scope should include the root of tongue, epiglottis, vocal cords, posterior wall of hypopharynx and other parts to observe whether there are lumps, ulcers, bulges and other symptoms. For further examination, if combined with dynamic laryngoscopy, the vibration of vocal cords can be further observed; if combined with narrow band imaging technology, tiny lesions on the mucosal surface can be clearly displayed, which is conducive to the discovery of early laryngeal cancer. In daily life, if there is any discomfort in the larynx, it is recommended to go to the hospital in time, and under the guidance of the doctor, carry out the corresponding examination to make a clear diagnosis.