In this paper, a new generation method for diamond turning non-axisymmetry aspheric mirrors is introduced. A rotary arm that carried a diamond tool combined with fast tool servo was used to replace the straight guides employed by most diamond turning machines. The micro linear feed of the fast tool servo was real-time calculated with the use of high resolution angular feedback on the work spindle and the swing tool. Synchronized motion of the fast tool servo according to rotating angles of the workpiece and the diamond tool produced ultra-precision non-axisymmetry aspheric surfaces. The corresponding mathematical models of NC program are presented.