Light guide rod is one kind of rod-shape optical integrator used for achieving good color-mixing. It is usually made of glass to match with high power multi-color LED. Good color-mixing performance depends on the precise optical design and manufacturing technology. The incident surface, integral length and exit surface of light guide rods have been accurately calculated and ground with high precision, and the surface quality reaches the level of imaging in optics, ensure excellent color-mixing but also gives consideration of high efficiency.