In the past decade, carbon reduction and environmental protection have become the emphasized issues in every country. LED is well-known for high efficacy and slim size; therefore, it has become an alternative replacement for traditional light source. Although LED features high efficiency and power saving, without appropriate optical complements, it may exist some shortcomings such as asymmetrical light pattern, light halo and it can’t be looked directly. Hence, secondary optical design is necessary to make the performance of LED similar to the traditional light sources. Secondary optical design is based on the principles of refraction and reflection so that the light which is emitted by LED can project on the desired lighting space. Moreover, secondary optical design can change the light angle and make lighting fixtures present the desired lighting effects.