Objective To investigate the efficacy and safety of step-by-step endovascular treatment strategy for patients with acute ischemic stroke (AIS) caused by intracranial atherosclerosis-large vessel occlusion (ICAS-LVO) of anterior circulation.Methods The clinical data of patients with anterior circulation ICAS-LVO-related AIS who underwent emergency step-by-step endovascular treatment in our center from Jan. 1, 2018 to Dec. 31, 2019 were retrospectively analyzed. According to the step-by-step treatment methods, the patients were divided into glycoprotein Ⅱb/Ⅲa inhibitor (tirofiban) infusion group (GPI group), GPI+ballon angioplasty (BA) group and GPI+BA+rescue stenting (RS) group. The rate of successful recanalization (modified thrombolysis in cerebral infarction grade ≥ 2b) immediately after operation, incidence of symptomatic intracranial hemorrhage after operation, and good prognosis (modified Rankin scale score ≤ 2) rate and mortality 90 d after operation were evaluated.Results Totally 69 patients (53 males and 16 females), aged 30-86 years, were included in this study, including 20 patients in the GPI group, 14 in the GPI+BA group and 35 in the GPI+BA+RS group. There were no significant differences in baseline data, such as gender, age, hypertension, diabetes mellitus, coronary heart disease, smoking or drinking, among the 3 groups (all P>0.05), except for the history of ischemic stroke or transient ischemic attack and National Institutes of Health stroke scale score before operation. Sixty-eight (98.6%) patients had immediate successful recanalization. After operation, the reocclusion rate of responsible vessels was 6.7% (4/60), and the incidence of symptomatic intracranial hemorrhage was 4.3% (3/69). Sixty-seven patients were followed up 90 d after operation, and 2 were lost. The good prognosis rate was 64.2% (43/67), and the mortality was 9.0% (6/67). There were no significant differences in the 90 d good prognosis rate, 90 d mortality, incidence of symptomatic intracranial hemorrhage or reocclusion rate of responsible vessels among the 3 groups (all P>0.05).Conclusion For patients with AIS caused by ICAS-LVO, the step-by-step endovascular treatment strategy is safe and effective.