Objective To optimize the Chest pain triad CT scan programs and the use of lower tube voltage to reduce the amount of contrast agent, reduce radiation dose. Methods divid the 34 cases Chest pain triad suspected by clinical were randomly into 100KV and 120KV two groups, using the direction of retrospective ECG-gated scan mode from bottom of heart to the aortic arch. Make subjective Evaluation for the reconstruction image of coronary by two high year diagnostic doctors, measuring the CT value of the two sets of data of pulmonary artery, the descending of aorta right coronary opening and right coronary artery beginning part, calculating the three images signal to noise ratio (SNR), calculating contrast noise ratio (CNR)and the effective radiation dose (ED), for statistical analysis. Results No difference in the coronary artery subjective scoring, pulmonary trunk and descending aorta SNR, pulmonary artery and the descending aorta and the opening of the right coronary CT value, right coronary artery opening image SNR, pulmonary trunk image and descending aorta image and right coronary artery opening image CNR, dose length product and effective radiation dose of the two sets data are different. Conclusion Change the scan direction from the heart bottom to the aortic arch for chest pain triad scan mode, while using low tube voltage can guarantee check the effect of the triad of chest pain, but also to achieve contrast and low radiation doses dual controlling, have more high clinical practical value.