针对LED作为舞台灯需要进行二次光学设计的问题，根据面向扩展光源的设计原理，提出一种反射式的大功率LED舞台灯的设计方法，实现对舞台背景幕布的大面积非对称均匀照明。在二维坐标系中建立反射面模型，控制目标面上某一点的两条边缘光线，使它们形成的光锥在目标面上逐点扫过，结合反射定律、边缘光线原理以及光学扩展量理论，得到反射面的母线上各点坐标，母线拉伸后得到反射面。利用TracePro软件对所设计的系统进行模拟仿真，结果表明，多个舞台灯的照明叠加，可在1.5~2.0 m的距离范围内实现宽20 m、高11 m的均匀照明，其均匀度可达80%，说明该结构适用于大面积非对称的均匀照明。

In view of the need for secondary optical design of LED as the stage light, a design for reflecting stage light with high-power LED is proposed to achieve the asymmetric uniform illumination on stage backdrop, according to the principle of extended light source. By creating a reflecting surface model in a two-dimensional coordinate system and controlling the two marginal rays of a certain point on the target surface, the light cone formed by the two marginal rays can sweep point by point. Combined with the laws of reflection, the edge ray principle and the étendue conservation theory, the coordinates of each point on the generatrix are obtained and then the reflection surface is generated after stretching the generatrix. The ray-tracing simulations with TracePro software show that by superposition of several stage lights, in the illuminated region of 20 m width and 11 m height within a distance range of 1.5~2.0 m, the luminous uniformity is able to reach 80%. Hence, this structure enables LED light source to be applied in wide-range lighting system to get uniform illumination.