End-milling of free-form surfaces on 5-sxis NC tools is a complex problem which has been studied by a large number of research scientists. When end-milling non-convex surfaces, there is a risk of interference between the tool and the surface. This paper presents a new approach to generate gouging-free tool path for constant scallop-height machining using 5-axis toroidal milling. Based on second-order approximations of the machined strip width, we present locally optimal cutting positions for cutting directions. The largest machined strip width of iso-scallop and the corresponding gouging-avoidance tool orientation are calculated. In the cutter path generation procedures, the master cutter paths have been chosen from the minimum curvature loci of the surface. The tool path generated by this method are also compared with that of the long edge of surface as the MCP, the results of simulation show that the method can yield a reduction in line segments of tool path . Velocity curve and acceleration curve are smoother.