The main functions of otorhinolaryngoscopy are: visualization of lesions in nasopharynx, oropharynx and laryngopharynx; endoscopic treatment. 1. Visual observation of lesions in nasopharynx, oropharynx and laryngopharynx: Due to the narrow space of human ear, nose and throat and many cavities, it is difficult to observe with naked eyes under normal circumstances, using the advantages of the cavity mirror, it can reach the narrow cavities, locate and diagnose the diseased parts accurately, and at the same time, it can differentiate between different diseases. Differential diagnosis can be made by cutting small pieces of tissue. 2. Endoscopic treatment: Another main role of ENT endoscopy is to provide a more delicate auxiliary role for ENT surgeries, which can be operated and operated under the instruction of ENT endoscopy, avoiding damage to unnecessary parts and completing surgeries with higher precision. At present, ENT endoscopy is widely used in ENT diseases and plays an important role in the diagnosis and treatment of the diseases.