Abstract: Objective To evaluate the safety and efficacy of perioperative infusion of different doses of dexmedetomidine in acute ischemic stroke (AIS) patients undergoing mechanical thrombectomy (MT). Methods AIS patients who underwent MT in Yidu Central Hospital from February 2020 to August 2021 were enrolled. According to the random number table method, they were divided into three groups:group RD1 (dexmedetomidine was given at the initial dose of 0.5 μg/kg within 10 min, and maintained at 0.2 μg·kg^-1·h^-1), group RD2 (dexmedetomidine was given at the initial dose of 0.5 μg/kg within 10 min, and maintained at 0.4 μg·kg^-1·h^-1) and group R (normal saline was given at the same rate). The following indicators were observed:baseline information before surgery, intraoperative hemodynamics before entry into the operating room (T0), before tracheal intubation (T1), immediately after tracheal intubation (T2), and at post- tracheal intubation 3 min (T3), 6 min (T4), 9 min (T5), 12 min (T6), 15 min (T7), 30 min (T8) and 45 min (T9), as well as the success rate of recanalization (mTICI ≥ 2b), time indicators, the consumption of narcotic and vasoactive agents, the consumption of sufentanil at postoperative 4 h, 12 h, 24 h and 48 h, pain intensity, level of sedation (LOS) and Bruggrmann comfortable score (BCS), surgeon satisfaction, the number of symptomatic intracranial hemorrhage cases, the incidence of cerebral infarction at postoperative 30 days, and mortalities at discharge and 90 days after stroke. Results Compared with group R, group RD1 and group RD2 showed significantly decreased heart rate at T1-T7, and increases in mean arterial pressure at T1-T4, as well as reduced consumption of sevoflurane and remifentanil during operation, shortened length of postanesthesthesia care unit stay, increased use of atropine and decreased use of urapidil and nimodipine, and improved surgeon satisfaction (P<0.05). There was no statistical difference in the success rate of recanalization(mTICI ≥ 2b), the consumption of sufentanil and pain intensity, LOS and BCS, the incidence of cerebral infarction at postoperative 30 days, and mortalities at discharge and 90 days after stroke among the three groups (P>0.05). Conclusions Perioperative combined application of dexmedetomidine can reduce the consumption of narcotic agents, improve surgeon satisfaction, and stabilize the hemodynamics for AIS patients undergoing MT. However, no obvious improvement can be seen in the mortality and functional prognosis of patients at discharge and 90 days after stroke.