Inclusion Criteria:  Eighty ASA Ⅰ - Ⅱ patients aged 3-13 years underwent elective surgery under general anesthesia. No serious cardiovascular disease, no liver and kidney dysfunction, no central nervous system disease and mental disease. Patients undergoing tonsillectomy under general anesthesia were selected as the research objects.  Exclusion Criteria:  ASA grade III and above, abnormal heart, lung, liver and kidney function before operation; There were central nervous system diseases and mental diseases, preoperative allergy to anesthetics (dexmedetomidine, esmketamine), family history of malignant high fever, tracheostomy and other artificial airway.