本篇研究利用自由曲面應用於路燈照明。設計規格針對雙向四線車道作路面照明，路燈間距30 m，每盞路燈針對單方向兩線車道30 m 10 m的範圍外加車道外5 m 寬的範圍作照明，路面材質以簡化輝度係數分佈較複雜的混合型瀝青路面，道路級別R2作設計。主要結構是以收斂杯將點光源的光發散角作收斂，再以自由曲面配合部分分配照射的方式控制光形為矩形指以及配合指向性照度分配優化法作出符合CIE 140-2000、CIE 115-2010道路照明法規的各項規範。矩形光形的控制能使單盞路燈獨立運作時也不會浪費能量，且因對於光形的控制自如也使得眩光非常的低。;In this thesis, we study in designing street lighting base on freeform. We design street lighting to lighting the road which is double way in four lanes. The specification of our street lighting including 30 m gap which between each street lighting. 30 m 10 m area of one way in two lanes and 30 m 5 m area of SR are lighting by each street lighting. We choose condition of R2 level of pavement in our designing, the material of R2 is asphalt mixture. R2 level of pavement has complicate distribution of reduced luminance coefficient and it makes designing difficultly. We use converging lens to converge the incident ray which come from LED source and using freeform lens with the method which is called lighting by parts to projecting rectangular light shape and using method which is called arrange illuminance directly to control freeform to get the illuminance distribution to pass the specifications of rule of street lighting. Because light shape is controlled greatly, it won’t waste energy and makes glare very low.