Abstract: To investigate the influence of waste baffle structure on the flow field and separation performance of a gas centrifuge, flow field distribution was obtained by numerically solving linearized Navier-Stokes equation with a finite difference method, based on which the separative power was calculated. Combined with iSight’s optimizing features, SQP algorithm was applied in numerical optimization of waste baffle structure parameters. The numerical results show that, for the specific model, circulation was modified and separation power was enhanced by 3.93% through optimization; the flow field was sensitive to the change of waste baffle structure parameters, mechanism of which is complicated and needs further research.