Background Eight randomized controlled trials have consistently shown that endovascular treatment plus best medical treatment improves outcome after acute anterior proximal intracranial large vessel occlusion strokes. Whether intravenous thrombolysis prior to endovascular treatment in patients with anterior circulation, large vessel occlusion is of any additional benefits remains unclear. Objective This study compares the safety and efficacy of direct endovascular treatment versus intravenous recombinant tissue-type plasminogen activator bridging with endovascular treatment (bridging therapy) in acute stroke patients with intracranial internal carotid artery or middle cerebral artery-M1 occlusion within 4.5 h of symptom onset. Methods and design The DEVT study is a randomized, controlled, multicenter trial with blinded outcome assessment. This trial uses a five-look group-sequential non-inferiority design. Up to 194 patients in each interim analysis will be consecutively randomized to direct endovascular treatment or bridging therapy group in 1:1 ratio over three years from about 30 hospitals in China. Outcomes The primary end-point is the proportion of independent neurological function defined as modified Rankin scale score of 0 to 2 at 90 days. The primary safety measure is symptomatic intracerebral hemorrhage at 48 h and mortality at 90 days. Trial registry number ChiCTR-IOR-17013568 ( www.chictr.org.cn ).