Aim The computational fluid dynamics (CFD) technique was used to simulate the changes of blood flow in different degrees of coronary artery stenosis, to explore the relationship between the change of coronary artery hemodynamics and different stenosis. Methods The right coronary arterial geometric model was reconstructed with CT images. The model of stenosis was defined as 0%(normal vascular), 30%(mildly stenosis), 60%( moderate stenosis) and 90%(severe stenosis), respectively. The model of vascular hemodynamics was established respectively. Numerical simulations were performed to compare the hemodynamics between the different vascular models. Results By comparing the hemodynamic numerical simulations of four kinds of stenosis, with the severe of the stenosis, the vortex flow becomes more obvious, the velocity of the flow showed faster in stenosis. In the proximal vascular region of stenosis, wall pressure (wall pressure, WP) was gradually increased; on the other hand, the WP showed lower in the region after the stenosis. The wall shear stress (WSS) distribution at the stenosis site always showed higher, and in the moderate and severe stenosis model, the high WSS region was found in the distal vascular region of stenosis, and the other distal vascular region of stenosis showed low WSS. Moreover, on the velocity and distribution of vascular blood flow, proximal and distal vascular region of the stenosis were also changed. Conclusion CFD based on CT images maybe reconstruct the coronary arterial hemodynamic model accurately, and the coronary arterial hemodynamic model with diverse stenosis may simulate coronary arterial stenosis. As hemodynamic risk factors, the vortex of stenosis posterior flow and the high WSS in the distal vascular region of stenosis which showed in moderate and sever stenosis model maybe aggravated atherosclerosis of coronary artery, and further aggravated the vascular stenosis.