According to the structure characteristics of a flow impeller in the automobile turbocharger, the emphasis and difficulties of processing were analyzed. The machining program of the flow impeller was programmed using non impeller module of UG software, the limitations of UG impeller module programming was broken through, the problem of the low efficiency and accuracy was solved, the machining quality of impeller was improved. Finally, this method was proved to have good application value by Vericut simulation and physical verification.