Laser Rapid Prototyping which is used in tooling the complex parts of blood pump is a good way in designing and developing the micro-axial blood pump model. We present the fundamental and methods of rapid prototyping and study in molding the complex screw blade by designing and manufacturing the blood pump model. By analysis of parts errors caused by tooling，the errors of the dimension precision is caused by the technique of layering and the material of resin of rapid prototyping and the technique of layering causes the appearance errors of screw blades.