Impeller 5-axis CNC machining process and processing content were analyzed. MasterCAM X6 software was used to generate five-axis roughing trajectory of the impeller, the impeller expansion tank and wheels finishing trajectory, blade finishing trajectory. VERICUT simulation software was used to make tool set, addition of the tool library, addition of rough, addition of impeller machining CNC program, setting collision and interference color display, program optimization etc. Through simulation, five-axis impeller without collision and undercutting was gotten.