Objective To investigate the influence of heart rate and blood vessel image quality and radiation dose changes in 640 slice spiral CT coronary artery imaging. Methods A total of 91 patients, male 51 cases, female 40 cases, average age is 58 years old. Divided into three groups, 30 cases in group A whose heart rate was equal or greater than 65 beats per minute; 30 cases in group B and the heart rate of them was greater than 65beats per minute but less than 80 beats per minute; 31 cases in group C whose heart rate was greater 80 beats per minute. After the scan completed, the most optimum phase was chosen for volume rendering (VR), maximum intensity projection (MIP), multi planar reconstruction (MPR) and curved planar reconstruction (CPR) to have vascular reconstruction, vascular image quality was classified according to the 4 points method and it was statistically analyzed. We recorded the radiation dose product of each group(DLP). Results The blood vessel image quality evaluation and the excellent and good rate in the proportion of the three groups had no statistical significance, the heart rate was negatively correlated with the quality grade of blood vessel image. A group DLP was (3.37±2.12) mGy.cm, B group was (4.78±1.92) mGy.cm, C group was (6.11±2.79) mGy.cm, radiation dose of three groups was statistically significant, the heart rate is positively correlated with the radiation dose. Conclusion 640 slice spiral CT coronary angiography can show the image better in patients with high heart rate, but also increase the radiation dose, we should reduced heart rate to 65 beats per minute below as far as possible with the condition permitted. To obtain excellent vascular image quality by lower radiation dose at the same time, is conducive to the sustainable development of coronary artery CT angiography imaging, so that more patients can be benefitted from it.