It is difficult to enrich isotope components of small abundance to a high concentration by means of gas centrifuge cascades. A nonsteady-state approach is studied for the separation of end components and middle components. Unlike ordinary conventional separation cascades, which have two withdrawals at the two ends of the cascades and one feed in between, the cascade used in the nonsteady-state approach has only one withdrawal at the either end and one feed. The nonsteady-state separation approach is analyzed from two aspects: the material recovery and the operation time efficiency, for producing one unit mass of material, and is compared with conventional cascades. The results show that the approach is advantageous over the conventional cascades for obtaining the same amount of a desired component, especially for the separation of end components.