PC has good strength and toughness, and its luminousness can be 89%. The impact resistance of PC is 250-300 times of glass, and 30 times of PMMA plate (with same ply). PC is a kind of amorphous thermoplastic resin with comprehensive performance. It has excellent electrical insulation, extensibility, dimensional stability, and chemical corrosion resistance. Because of the mechanical strength, big-sized parts are difficult to be made with 3D printing. Therefore, CNC machining PC prototype has more advantages for big-sized prototype.