Objective　The study is based on digital subtraction angiography to evaluate the capillary status and the correlation between the efficacy and prognosis of endovascular treatment of acute anterior circulation ischemic stroke,and to explore the protective effect of collateral circulation in the process of reperfusion therapy.Methods　A retrospective analysis of patients with acute anterior circulation aortic occlusion within 24 hours of onset from January 2020 to December 2020.The capillary index score (CIS) was used to evaluate the collateral circulation of the responsible vascular area of the ischemic brain tissue,and the final infarct volume and the DWI image results of the head MRI within 1 week after the operation were calculated based on the core infarct volume of CTP perfusion imaging and Progress in infarct volume,and follow-up to evaluate the clinical prognosis and long-term functional recovery of patients.Results　(1)Baseline ASPECTS score (OR=2.246,95%CI 1.084~6.328,P<0.05) middle cerebral artery M1 or M2 occlusion (OR=4.801,95%CI 2.047~11.261,P<0.001) is a collateral branch independent influencing factors of the cycle.(2)Baseline ASPECT score (OR=6.476,95%CI 1.618~21.921,P<0.001),collateral circulation (OR=12.304,95%CI 5.035~28.348,P<0.01) and discharge NIHSS score (OR=0.637,95%CI 0.473~0.858,P<0.01) is an independent factor influencing the 3-month prognosis of patients with thrombus removal.Conclusion　Assessment of capillary status based on DSA has a good predictive effect on the progression of infarct volume and clinical prognosis of patients with acute anterior circulation aortic occlusion within 24 hours of onset.The combination of collateral circulation and onset time window can help to screen the possible gains in endovascular treatment.Benefit of AIS patients.