〔Abstract〕 Objective To analyze the effect of carotid artery stenting (CAS) on cognitive function in patients with severe internal artery stenosis. Methods A total of 78 patients with severe internal carotid artery stenosis admitted to Nanyang Central Hospital from August 2020 to August 2021 were selected and randomly divided into an observation group and a control group with the random number table method, 39 cases in each group. The control group received carotid endarterectomy (CEA), and the observation group received CAS. The postoperative follow-up was 6 months, and the operation effect and cognitive function improvement were compared between the two groups. Results There was no significant difference in the scores of Montreal cognitive assessment (MoCA), mini-mental state examination (MMSE), verbal fluency test (VFT), Benton visual retention test (BVRT) and activities of daily living (ADL) between the two groups before operation (P > 0.05). 6 months after operation, the scores of MoCA, MMSE, VFT, BVRT and ADL in the observation group were higher than those in the control group, and the differences were statistically significant (P < 0.05). The incidence of complications in the observation group was 2.56% , lower than 15.38% in the control group, and the difference was statistically significant (P < 0.05). Conclusion CAS with short operation time, the trauma is small, it can quickly clear the carotid artery, increasing blood oxygen in the brain, improve the cognitive function of the severe internal artery stenosis patients, has less complications