Objective To observe the application of CT angiography (CTA) and CT perfusion (CTP) in diagnosis and treatment of acute cerebral infarction. Methods A total of 52 cases of patients with acute cerebral infarction treated in our hospital from January 2016 to June 2017 were selected and given CT plain scan, CTA and CTP. And the related data were analyzed. Results There were 33 cases without obvious abnormalities and 19 cases with ischemic lesions among 52 cases by CT plain scan. The results of CTP examination showed that there were cerebral perfusion abnormalities areas among 52 cases which were consistent with clinical symptoms, and the cerebral blood volume (CBV) and peak enhancement (PE) with (2.31±0.56) mL/100g and (4.49±0.51) Hu in the infarction area were significantly lower than those in the contralateral corresponding area with (4.47±1.28) mL/100g and (7.20±0.93) Hu (P<0.05), and the time to peak (TTP) and mean transit time (MTT) with (13.02±1.18) s and (38.39±3.41) s respectively were significantly longer than those in the contralateral corresponding area with (9.95±1.03) s and (34.06±2.75)s (P<0.05). A total of 57 vascular lesions were found in 52 cases, and there were 4 cases of moderate stenoses, 1 case of severe stenosis and 1 occlusion in anterior cerebral artery, and there were 5 cases of moderate stenosis, 5 severe stenosis and 4 occlusions in middle cerebral artery, and there were 3, 2 and 2 in posterior cerebral artery, and there were 4 mild stenosis, 5 moderate stenosis, 2 severe stenosis and 1 occlusion in base artery, and there were 6 mild stenosis, 8 moderate stenosis and 4 occlusions in intracranial segment of internal carotid artery. Conclusion CTA combined with CTP is easy to do, and it can determine the infarct area, the blood flow changes and the vascular stenosis of acute cerebral infarction better, and it has high clinical values for diagnosis and treatment.