提出了一种自由曲面准直透镜的优化设计方法。通过对二次B 样条理论、Scheme 语言和优化引擎的结合使用，实现了准直透镜的优化设计。采用1 mm×1 mm 朗伯体发光的LED 作为光源，透镜材料为聚甲基丙烯酸甲酯(PMMA)，通过对两款不同结构准直透镜的优化设计，可以实现发散角为±5° 的准直照明，能量利用率均可达90%以上。与现有的优化方法相比较，此方法具有对初始模型依赖较低、设计方法简单和普适性高等特点。

An optimization design method of collimating lens is proposed. The quadratic B-spline theory, Scheme language and optimization engine are used in combination to achieve the optimization of freeform surface lens. The Lambert emission of 1 mm × 1 mm LED is used as light source, and the lens material is polymethyl methacrylate (PMMA). The collimating lenses of different structures are optimized by this way. The energy efficiency can be up to 90% . Compared with the current methods, it has the advantages of less dependence on the initial model, simple design process and high versatility.