Abstract: A dual approach of combining accurate B-rep object model with approximate Cuboid-array model is introduced. Cuboid-array model inherits the advantages of Z-buffer‚Dexel and ray-casting methods‚greatly simplifies interference checking by fulfilling one-dimensional Boolean operation‚and is used to present the overall machining accuracy of workpiece；While accurate B-rep is used to present the whole machining process‚showing the current status of each interference zone.In such a way‚high quality rendering of machining process along with high precision of machining process verification are guaranteed quite easily.