Cutter design method and cutter machining path generation method

The embodiment of the invention provides a tool design method and a tool machining path generation method. The tool design method comprises the steps that a first contour line and a second contour line of a to-be-machined curved surface are obtained; generating at least three normal planes of the first contour line; reference circles which intersect with the first contour line and the second contour line respectively and are equal in radius are generated on the normal planes, the radius of each reference circle is determined based on the curvature of the curved surface to be machined, and points, intersecting with the first contour line or the second contour line, on the reference circles are mark points; taking one of the reference circles as a base circle, overlapping the other reference circles to the base circle, and projecting the mark points to the base circle; and the inferior arc is cut out from the reference circle with the two mark points with the largest interval as cut-out points, and the outline