5-axis CNC machining is one kind not only may realize the ordinary machining, but may also complete from the rough cutting to the post processing entire flow new cutting way. This article develops special software to plan cutting path for ruled surface impellers. By fitting sampling data points of an impeller blade into a curve, a model of ruled surface blade of an impeller is built up. Furthermore, by calculating the points where the cutter axis vector intersects the free-form hub surface of an impeller, problems about. Finally, an integral impeller cutting path is planned by way of an integrated cutter location control algorithm. Simulation and machining tests with an impeller are performed on a 5-axis computer numerically controlled (CNC) mill machine. A cutting path is generated by using ruled surface impeller CAM software and put into test, of which the result shows the feasibility of the algorithm and its practical worth.