Direct laryngoscopy and indirect laryngoscopy both belong to laryngoscopy and differ in operation method, anesthesia, clinical application and examination effect. 1. Methods of operation: direct laryngoscopy patients must lie on their backs, enter through the mouth, pick up the tongue, epiglottis, observe the larynx. Indirect laryngoscopy also enters from the mouth, pulls down the anterior 1/3 of the tongue, and changes the position of the laryngoscope for observation. 2. Anesthesia: direct laryngoscopy requires general anesthesia, indirect laryngoscopy most do not need anesthesia. 3. Clinical application: direct laryngoscopy is generally applicable to surgical operation and examination or microscopic resection, while indirect laryngoscopy is not considered as a surgical treatment means, but only a kind of examination. 4. Examination effect: direct laryngoscopy observation effect is clearer, indirect laryngoscopy examination effect may be affected by tongue hypertrophy or poor elevation of epiglottis.