Aspheric surfaces are widely used in modern optical systems. At present, five-axis machine tools are widely used for aspheric surfaces grinding and shaping. The technology of milling aspheric surface with five-axis machine tool is studied. According to the B-C double turntable five-axis machine tool, its kinematics model is analyzed. The tool path algorithm of rotating symmetrical aspheric cup grinding wheel is studied. A five-axis machine tool processing model of cup grinding wheel is established. By calculating contact points, planning tool axis vector and surface vector. The mathematic mapping between tool axis vector and rotation angles of B and C axes is obtained, and the algorithm model of tool path based on vector method is established. Finally, the aspheric surface with diameter 100mm, quadric surface coefficient k=-1 and curvature radius 300mm is machined by five-axis machine tool through simulation and example analysis with MATLAB. The result is measured by three-coordinate measuring instrument, and the PV value of the surface is 5.25um. The RMS value is 0.88um, which verifies the correctness of the tool path algorithm for cup grinding wheel.