A new special-purpose optical coordinate measuring machine (OCMM) was developed with the cylinder coordinates to realize full aperture testing of the optical aspherics in the stage of grinding and pre-polishing. The full-aperture of optical aspherics can be measured with testing several meridians point by point. In the aspect of hardware

the system was composed mainly by an ultra-precise air-rail for the linear motion

and a graduator for the rotary motion. In the aspect of software

for analyzing the mathematical model of a system

a new algorithm for the full-aperture testing of rotational-symmetric aspherics was astablised. The testing software and data-processing software were written on the VC++6.0 and Matlab platform respectively. The system is shown the better performance in the maximum measurement range of 600 mm

the maximum sag of 25 mm and the minimum sampling step of 1 mm. After the compensation of the systematic errorsthe accuracy is higher than 1 μm in full scale. The experimental results conclude that the optical coordinate measuring machine has a good universal and can satisfy requirement in the grinding and pre-polishing process for asphere testing.