【Abstract】 Objective To evaluate the value of cervical vascular ultrasound in the diagnosis of subclavian steal syndrome (SSS). Methods The data of 140 SSS patients admitted to our hospital from January 2021 to December 2023 were analyzed retrospectively. Taking Digital Subtraction Angiography (DSA) as the gold standard, the consistency of the degree of arterial stenosis, the classification of stolen blood and the ways of stealing blood were analyzed. Results Cervical vascular ultrasound and DSA were in good agreement in judging the degree of subclavian artery stenosis. Among 140 SSS patients, 120 cases (85.72%) had sclerotic plaques at the beginning of subclavian artery. Block, 8 cases (5.71%) of subclavian artery and innominate artery showed moderate echo plaque-low echo plaque, and 12 (8.57%) of the patients had no plaque formation. In 50 cases (35.71%), complete cranial outflow direction blood flow was observed in the affected vertebral artery, and in 114 cases (81.43%), alternating red and blue bidirectional flow was observed in the vertebral artery lumen. In all 140 patients, the healthy vertebral artery supplied blood to the affected side, the basilar artery supplied blood to the affected vertebral artery in 14 cases and the affected occipital artery supplied blood to the affected vertebral artery in 18 cases. Conclusion Cervical vascular ultrasound has high application value in the diagnosis of SSS and is suitable for popularization.