Ultraprecise turning method of optical lens with incline

The invention belongs to the technical field of manufacture and ultraprecise processing of optical elements, and relates to an ultraprecise turning method of an optical lens with an incline, which comprises the steps of: taking two datum points on the incline, determining a workpiece initial plane, roughly processing on the incline to be processed; making a fixture and assembling the workpiece on the end face of a processing lathe, regulating the workpiece initial plane to be vertical to the z axis, regulating a workpiece center to be coincide with a main shaft center; and carrying out coordinate conversion to obtain a connecting line of two end points to be coincide with the x axis, calculating a normal angle of the whole curved surface with center coordinates of the two datum points as a new curved surface of the original point, determining a diamond tool rear angle required by processing the curved surface, selecting a proper tool to be assembled on the lathe, carrying out NURBS (Non-Uniform Rational B-Spline) curved surface fitting on the curved surface subjected to the coordinate conversion, and determining the processing path according to a spiral drive line method. The lens surface is leveled by the coordinate conversion, and the tool rear angle required by processing the curved surface is reduced, thus the processing efficiency and the size of the processing workpiece can be increased, and the method is suitable for processing the large-incline optical lens with any gradient and Sag value.