Abstract: On the basis of analyzing the problems of the product design, the probability approach to study the principle and method for product quality design is used according to indeterministic information of design, and the applied software of design QC-ROD is developed. A hidden peril of quality will be as far as possible removed or no defective product will be obtained through these design techniques in a design process. So it has very important meanings to popularize and apply this method to develop and design a new product for the market competition.