Objective To explore the application value of treatment efficacy of 64-slice CT perfusion imaging (CTP) in the carotid angioplasty and stenting (CAS). Methods The preoperative and postoperative CTP perfusion images (64-slice CTP was given at 1d before CAS and at 5d after operation) of 200 patients with unilateral internal carotid artery stenosis who were given CAS treatment in our hospital from November 2016 to April 2018 were analyzed retrospectively. The front, middle and back points of the white matter area of centrum semiovale were taken as reference, and the cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) measured in the white matter of corresponding parts of bilateral internal carotid artery blood supply area. The relative values rCBF, rCBV and rMTT were calculated based on the contralateral value in corresponding parts. Results There was no significant difference in the CBV between affected side and contralateral side before CAS (P>0.05). The CBF of affected side was significantly lower than that of contralateral side before CAS, and the MTT was significantly prolonged (P<0.05). rCBF increased significantly after CAS while rMTT was significantly shortened (P<0.05). Conclusion CTP can reflect the cerebral perfusion in patients with internal carotid artery stenosis sensitively, and is a reliable method to evaluate the treatment efficacy of CAS.