Objective To analyze the diagnostic value of head and neck CT angiography for ischemic stroke. Methods 750 patients with suspected ischemic stroke who were admitted to our hospital from January to December 2020 were examined by carotid ultrasound (control group) and head and neck CT angiography (observation group). The examination data of the two groups were analyzed by comparing the results of digital subtraction angiography. Results Among 750 patients, 650 were diagnosed with ischemic stroke caused by carotid artery stenosis by digital subtraction angiography, accounting for 86.7% (P<0.05); the accuracy, specificity, and sensitivity of head and neck CT angiography in the observation group were significantly better than those in the control group (P<0.05); the detection rate of carotid artery stenosis using head and neck CT angiography in the observation group was significantly higher than that using carotid artery color Doppler ultrasound in the control group (P<0.05). Conclusion CT angiography of head and neck has high accuracy, specificity and sensitivity in the diagnosis of acute ischemic stroke, and its imaging characteristics are very typical.