Acute ischemic stroke (AIS) has been one of the major causes of global mortality and morbidity. The superiority of endovascular therapy (EVT) over standard medical therapy in treating AIS due to large vessel occlusion (LVO) in the anterior circulation has been widely accepted. However, a critical concern is that even with an extremely high rate of successful recanalization (the modified thrombolysis in cerebral infarction [mTICI] score 2b-3) around 90%, nearly half of the patients failed to benefit from EVT. So, adjunctive therapy of EVT for neuroprotection is required. From the previous domestic and foreign literatures, hypothermia can prevent and treat secondary injury caused by ischemia-reperfusion injury and cerebral edema of acute cerebral ischemia, so as to achieve the role of neuroprotection. In this study, intravascular cooling was performed as soon as possible with careful temperature control in patients receiving thrombectomy. The temperature was controlled at 33° C for 48-72 hours. This parallel controlled study is to systematically evaluate the feasibility and safety of adjunctive therapy using early intravascular hypothermia in AIS patients receiving mechanical thrombectomy. The results will clarify a potential modality for neuroprotection and hopefully provide new evidence in improving patient prognosis.