Abstract： Objective To investigate the effect of ultrasound guided bilateral superior laryngeal nerve block combined with intravenous general anesthesia on perioperative stress response in patients underwent radical thyroidectomy for thyroid canc-er.Methods This study was a prospective study.84 patients who underwent radical thyroidectomy for thyroid cancer were in-cluded in this study.They were randomly divided into 2 groups using a random number table method,with 42 patients in each group.The control group received routine intravenous general anesthesia,while the observation group received ultrasound guided bilateral superior laryngeal nerve block combined with intravenous general anesthesia.The hemodynamic indicators[heart rate(HR),mean arterial pressure(MAP)]and stress response indicators[adrenaline(E),norepinephrine(NE)]were compared be-tween the 2 groups of patients 30 minutes before anesthesia induction,during intubation,and during extubation.The pain levels at 3,12,and 24 hours after awakening from anesthesia between the 2 groups[evaluated using visual analogue scale(VAS)]and the occurrence of adverse reactions to anesthesia within 72 hours after surgery were compared.Results The HR and MAP of both groups increased 30 minutes before anesthesia induction,during intubation,and during extubation,but compared with the control group,the HR and MAP of the observation group were lower during intubation and extubation(P＜0.05).The levels of E and NE in both groups increased 30 minutes before anesthesia induction,during intubation,and during extubation.However,compared with the control group,the levels of E and NE in the observation group were lower during intubation and extubation(P＜0.05).At 3 hours,12 hours,and 24 hours after awakening from anesthesia,the VAS scores of both groups increased,but compared with the control group,the VAS scores of the observation group were lower at all time points(P＜0.05).Compared with the control group,the observation group had a lower overall incidence of adverse reactions to anesthesia within 72 hours after surgery(P＜0.05).Conclusion Ultrasound guidance bilateral superior laryngeal nerve block combined with intravenous general anesthesia can re-duce perioperative stress response,maintain hemodynamic stability,improve postoperative analgesic effect,and help reduce postop-erative adverse reactions in patients undergoing radical thyroidectomy.