Objective To evaluate the effect of CT on the coronary angiography guided by Doppler ultrasound. Methods A total of 116 patients with coronary artery disease who were examined by CCTA in February 2016 to February 2017 were selected as the study subjects. Patients were divided into observation group and control group by random number table method. The control group underwent CCTA examination with traditional prospective ECG gating, and the CCTA was examined under the guidance of ultrasonography. Results Among the 1672 coronary arteries in 116 subjects, 78 segments were not included in the statistics because of the small blood vessels, and 1594 segments were analyzed after removal. There was no significant difference between the two groups in the image quality score (P>0.05). There was no significant difference in sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy between the patients, the branch, the segmental coronary artery lesion, the control group and the observation group (P>0.05). The radiation dose (2.15±0.36) mSv in the observation group was significantly lower than that in the control group (9.75±0.92) mSv (P<0.05). Conclusion Compared with the traditional prospective ECG gating method, Doppler-guided prospective ECG gating can further reduce the effective radiation dose while ensuring the diagnostic accuracy and image quality.