Abstract: In order to seek the shortcut method based on experimental designing method for the cascade system used in the light isotope separation, the optimization design of three cascades system for the stable isotope ¹³C separation by carbon monoxide (CO) cryogenic distillation using uniform design method was taken as an example. The annual total cost of the cascade system was the testing index, the relative withdrawal of the stages and the enrichment degree of the key component were the decision variables. The mathematical model of the cascade annual total cost relative to the decision variables was obtained by means of the regression analysis of the results of uniform designs. Then the decision variables at the minimum annual total cost can be figured out, which can be used to calculate the cascade craft. The mathematical model of the annual total cost of the cascade system relative to the decision variables was obtained by means of the regression analysis of the uniform design experimental results using software DPS. And the cascade parameters at the minimum annual total cost were gotten through the model.