Abstract: Objective:To evaluate the right ventricular function in coronary CTA by multi-stage double-flow mass injection. Materials and Methods:100 patients who underwent cardiac CTA from October 2017 to October 2018 in our hospital were selected to exclude the patients whose heart rate was too fast and needed drug control, patients with atrial fibrillation and those who were allergic to contrast agents. All 100 patients underwent 128-slice MSCT examination. Fifty patients(group A) were randomly divided into two groups, 29 males and 21 females, with an average age of(61.30 ±11.99) years, and underwent multi-stage double-flow balloon coronary angiography.(Group B) as the control group, 33 males and 17 females, with an average age of(56 ±9.64) years, underwent two-stage mass coronary angiography. Ten phases were reconstructed at 10% interval between the original data of the two groups and the whole cardiac cycle was included. Ten phases were transmitted to IntelliSpace Portal 5.0 workstation for coronary artery analysis and right ventricular function analysis. To compare the display effect of two injection methods on coronary artery and right ventricle, and evaluate the role of two injection methods in the evaluation of right ventricular function. Result:(1) The blood vessel images obtained from the 100 cases enrolled in this study can be used for clinical diagnosis, and there are no 0 cases. There were 2 cases in group A, 27 cases in group 2 and 21 cases in group 3, and 4 cases in group B, 18 cases in group 2 and 28 cases in group 3.(2) A total of 126 diseased vessels were found in 100 patients, including 65 in group A and 61 in group B. According to the classification of vessel names, 58 LAD, 32 LCX and 36 RCA were found.(3) Both methods can judge the stenosis of blood vessels and determine the extent of stenosis.(4) The interventricular septum in group A was clearly displayed in 44 cases, only 6 cases could not be displayed, while in group B, only 8 cases could be clearly displayed, while in the other 42 cases, the interventricular septum was not displayed.(5) The diameter of aorta was(34.26 ±4.28) mm in group A and(32.63 ±3.65) mm in group B. The diameter of aorta and pulmonary artery was(24.81 ±3.73) mm in group A and(24.56 ±3.10) mm in group B. The left ventricular ejection fraction was(62.72 ±7.16) in group A and 55.98 ±5.67 in group B. The right ventricular ejection fraction was 49.58 ±5.40 in group A and 45.90 ±5.31 in group B. Conclusion:Multi-phase dual-flow coronary CTA can improve the contrast of the right heart and clearly show the interventricular septum. It can evaluate the right ventricular function without affecting the degree of coronary artery stenosis, and it does not need to increase the radiation dose of additional scanning. To provide accurate, rich and multi-dimensional imaging information for the clinical diagnosis and treatment of patients with suspected right heart disease.