Objective The purpose of this study was to investigate the value of ultrasound-guided carotid sinus block in carotid stenting(CAS)．Method A prospective single—center randomized controlled study was conducted on 145 patients with intemal carotid artery stenosis receiving CAS from January 2017 to June 2019．Patients were randomly divided into group A (n=73)treated with local anesthesia of the carotid artery sinus guided by ultrasound preoperatively and group B(n=72) without local anesthesia．To observe whether there were adverse reactions during carotid sinus nerve block and record the block time and anesthesia dose in group A.The incidence of bradycardia

hypotension and stroke were monitored and compared between the two groups.Results The preoperative general data of the two groups were comparable (P > 0.05)．The proportion of patients with intraoperative hypotension and bradycardia in group A was 4/73 and 12/73

respectively

which were all lower than 16/72 and 35/72 in group B

(P < 0.05).In group A

no cardiac arrest or stroke occurred during perioperative period

while in group B

1 cardiac arrest occurred during the operation and 3 stroke events occurred after the operation，The total incidence of perioperative cardiac arrest and stroke in patients A was lower than that in group B (5.56%)(P < 0.05).There was 1 case of droop of upper eyelid of the affected side during carotid sinus nerve block in group A

and the patient recovered after restt.The two groups of patients allsuccessfully completed the operation.Conclusion Preoperative ultrasound-guided carotid sinus nerve block on the affected side can reduce the occurrence of intraoperative hemodynamic instability. This technique is workable

safe and feasible

and worthy of further clinical application.