In this paper, it is first proposed that genetic algorithm and Taguchi method can be employed in the optimal design of DC-DC converter with RCD snubber. The purpose of this optimal design is to lower the spike voltage V dsp of power switch and hence reduce the cost in manufacturing circuit. It is of great educational value for students and engineers. For the first step, we investigate the circuit parameters which will affect V ds and subsequently converge the range of circuit parameter by means of genetic algorithm and conduct the optimal design of prototype circuit with Taguchi method. Compared with spike voltage of non-optimal design circuit V dsp, the effect of optimal design is revealed. In suppressing voltage spike, the Vdsp measured from optimal design circuit is 210V, and is actually 8.2% reduced. Therefore, using genetic algorithm and Taguchi method in the optimal design of converter with RCD snubber is a more economic, practical and efficient of circuit design, which meanwhile can be easily applied to other electronic circuits and accomplish the optimal design of various quality characteristics.