Abstract: Quasi-ideal cascade is often used as a model cascade to design and optimize the cascade for multicompoment isotope-mixtures with large separation factor. It’s feasible to determine cascade configuration parameters on the condition that the concentrations of target component in the product and waste flows are given. Besides its own parameters, the separative performance of the optimal cascade will also change with the operating conditions of centrifuge. Through the intermediate variable, which is the overall separation factor, the influence of the operating conditions of centrifuge on the structure parameters and the separative performance of cascade was studied. Meanwhile, for separation of the middle component of Xe, the result of the structure parameters and the total substance flow of optimal cascade with different operating conditions of centrifuge was presented. And then the optimal operating parameters of centrifuge for separating the middle component of Xe isotope by cascade are obtained.