Objective To investigate the application value of ultrasound，superb microvascular imaging (SMI), and contrast enhanced ultrasound (CEUS) in the assessment of carotid artery stenosis (CAS). Method A total of 100 patients with stenosis and occlusion of carotid artery, subclavian artery, and vertebral artery，who were enrolled in our Hospital from January 1st 2018 to December 31st 2018, were included. All patients signed informed consent, then the patients were confirmed by digital subtraction angiography (DSA). Conventional ultrasound, superb microvascular imaging (SMI), and contrast-enhanced ultrasound (CEUS) were applied for determination simultaneously. According to NASCET's standards, vascular stenosis degrees of three diagnostic methods were calculated, and all diagnoses were relatively conducted by two physicians. The consistency of ultrasound, SIM, and CEUS to diagnose CAS in patients were comparatively analyzed with the results of DSA as a golden stadard. The sensitivity, specificity and predictive values of three methods were compared. Results The fine vascular structures were clearly showed by all three methods, including the characteristics of vessel and exact position of plaque, volume of vessel lumen, and spatial distribution of blood flow direction in the carotid artery stenosis. In the diagnosis and evaluation of CAS, the degree of carotid artery stenosis by conventional ultrasound was highly consistent with DSA (κ = 0.869), and the sensitivity, specificity, and accuracy of severe stenosis and occlusion (> 70%) were 90.0% (95% CI: 0.86, 0.94), 94.0% (95% CI: 0.91, 0.97), and 90.0% respectively. The degree of carotid artery stenosis detected by SMI was highly consistent with DSA (κ = 0.958), and the sensitivity, specificity, and accuracy of diagnosing severe stenosis and occlusion were 96.0% (95% CI: 0.93, 0.99), 97.0% (95% CI: 0.95, 1.00), and 97.0%, respectively. CEUS was highly consistent with DSA (κ = 0.903), with sensitivity of 96.0% (95% CI: 0.93, 0.98), specificity of 94.0% (95% CI: 0.90, 0.98), and accuracy of 94.0% in diagnosing severe stenosis and occlusion. In terms of the sensitivity and specificity of assessing the degree of severe carotid artery stenosis of three methods were not statistically significantly different (P > 0.05). Conclusion Conventional ultrasound, SMI, and CEUS have high accuracy and sensitivity in diagnosing degree of carotid artery stenosis. SMI has the advantages of economics, convenience, rapidness, and non-invasion, and has high clinical application value. It may replace other imaging examination methods for clinical screening CAS.