LED 的二次光学元件设计对LED 路灯的配光及光学输出效率至关重要。文章针对大功率LED在路灯上的应用，基于选定的LED进行了一种用于LED路灯的自由曲面二次光学透镜的设计，并采用光学软件进行仿真。结果表明，采用非对称自由曲面二次光学元件可以实现LED路灯的矩形配光，采用这种LED模组组成的路灯便于结构设计、电源安装, 不同功率的LED路灯只需要增加不同数量的LED模组即可。此种设计可以在很大程度上提高LED路灯的效率，提高路面照明的均匀度。

The secondary optics design is a critical issue for the output efficiency and light distribution pattern of the LED street light. Aiming at the application of large power LED in street light, based on LED has been developed，the calculation methodology of a freeform optics for the street light is put forward and simulated with the optical software. The result shows that the single LED module adopt the unsymmetrical freeform optics can make a rectangular light distribution. The mechanism and the power control electronics of the LED street light becomes very simple, different power LED street light only need to increase the different number of LED modules. And this design promotes the efficiency of LED street light in a large scale and greatly improves the uniformity of illumination on the street.