On the basis of the Lambertian light emission pattern of LED, Hybird Taguchi-Genetic Algorithm (HTGA), the combination of the Taguchi method and the process of traditional Genetic Algorithm, is adopted to make optimal design of the TIR lenses used as beam shaper, the purpose is to meet the uniform illumination requirement of specific target surfaces. This algorithm uses the construal parameters as chromosome and constructs the evaluation function based on the illumination result of specific target surface, by which the structural parameters of TIR lens can be achieved. The whole process is performed on the platform based on the Matlab and TracePro. Results show that HTGA algorithms, along with parameter design features of the Taguchi method during the entire optimization process, can improve the performance of the traditional GA algorithm. With the light efficiency reaching 60%, the optimized TIR lens can efficiently improve the illumination uniformity on the target surface to 88%.