Abstract: Image matching is an important part of the field which is about reverse engineering CAD modeling,For the matching problem of CT images which contain bifurcation outline, ellipse-fitting was used to quantitative describe the completed shape and locating information for the series of discrete contour points,thus a elementary contour forest can be established. Speedy HD distance method was used to deal with the issue of branches to form a complete contour forest. Experimental results show that the algorithm to imatch images with good accuracy and real-time processing capability. It is useful to match CT images of rock heart, industry and medical.