In the base of extracting vascular centerline using skeletonization algorithm, the tracking method of coronary vessel diameter measurement based on Measure of Match (MoM) evaluation model was proposed. The algorithm took account of the symmetry between the two edge lines of blood vessels and the centerline, and the optimized evaluation idea. By the quantitative measurement of the actual image and comparison with the actual diameter, it was found that using the proposed method can accurately measure blood diameter, and can effectively address the overlap of vascular branching and diameter measurement problems.