Objective: To analyze the application effect of CT whole brain perfusion (CTP)+CT angiography (CTA) in the diagnosis of acute cerebral infarction. Method: Study period: January 2023 to January 2025, reference subjects: 50 patients with acute cerebral infarction. All patients underwent CTA and CTP examinations, with whole-brain angiography (DSA) as the gold standard, and the results of the combined diagnosis of CTP and CTA were analyzed. Result: DSA examination detected 44 positive cases and 6 negative cases, and combined examination detected 44 positive cases and 6 negative cases. The diagnostic efficacy of CTA, CTP, and combined examination was compared with P > 0.05. One false positive case of combined examination was due to vascular hyperplasia in Moyamoya disease, and one false negative case was due to occlusion of the perforating artery; Two cases of false positive CTA were vascular spasm, and four cases of false negative CTA included two cases of distal branch occlusion and two cases of mild stenosis; Three cases of false positive CTP were blood flow changes during migraine attacks, and six cases of false negative CTP were small infarcts in the posterior circulation. The consistency between the combined examination and DSA was the highest (Kappa = 0.896). Conclusion: CTA combined with CTP for diagnostic examination can greatly improve the accuracy of early diagnosis of acute cerebral infarction through complementary integration of structural and functional information, providing a more reliable imaging basis for clinical treatment decisions.