Objective To explore the evaluation value of multi-parameter quantitative indicators of magnetic resonance imaging in the assessment of collateral circulation and prognosis of acute cerebral infarction (ACI). Methods A retrospective analysis was conducted on the clinical and magnetic resonance imaging (MRI )data of 80 patients with ACI admitted to Luoning County People’s Hospital from June 2022 to June 2025. All patients underwent head MRI examination within 48 hours after admission to obtain relevant imaging data. The differences in various MRI parameters among different collateral circulation states and different prognosis groups were compared, and the specific predictive value was analyzed. Results The infarcted area in the group with good collateral circulation had higher relative cerebral blood flow (rCBF) and relative apparent diffusion coefficient (rADC) compared to the group with poor collateral circulation (all P＜0.05); the rCBF and rADC values in the group with good prognosis were higher than those in the group with poor prognosis (all P＜0.05). The area under the curve (AUC) of rCBF for evaluating the collateral circulation status was 0.901; the AUC of rADC was 0.863; baseline National Institutes of Health stroke scale (NIHSS) score, rCBF, and collateral circulation status were independent risk factors for poor 90-day prognosis of patients. Conclusion The multi-parameter quantitative indicators based on magnetic resonance are closely related to the collateral circulation status and long-term prognosis of patients with ACI. rCBF and rADC have good assessment value for collateral circulation. This study is a retrospective analysis, and the conclusion needs to be verified by further prospective studies.