Objective: To evaluate the efficacy of the combined application of cervical vascular ultrasound (CVUS) and CT angiography (CTA) in the grading diagnosis of carotid artery stenosis (CAS). Methods: The imaging data of 92 CAS patients who underwent CVUS, CTA and DSA examinations from January 2020 to December 2024 were collected in our hospital. DSA was the "gold standard", and the diagnostic value of CVUS, CTA alone and combined examinations in different degrees of stenosis was compared. Results: DSA examination revealed a total of 115 narrowed blood vessels, including 68 with stenosis degree ≥70% and 47 with stenosis degree ＜70%. For 115 narrowed blood vessels, CDUS detected 64 positive and 51 negative, CTA detected 68 positive and 47 negative, and combined examination detected a total of 76 positive and 39 negative. The results of the combined diagnosis of CAS and DSA showed high consistency (Kappa=0.784, 0.815, P<0.001). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the combined diagnosis of CAS were 98.53%, 80.85%, 91.30%, 88.16%, and 97.44%, respectively, which were significantly higher than those of CDUS detection alone (P<0.05). The ROC curve results showed that the AUC of CDUS, CTA, and their combined diagnosis of carotid stenosis grading were 0.809 (95%CI: 0.724~0.893), 0.892 (95%CI: 0.824~0.960), and 0.897 (95%CI: 0.827~0.967), respectively. Conclusion: CVUS and CTA are both effective diagnostic methods for CAS, and their combined diagnostic effect is more consistent with DAS.