Laser interferometry measurement using the volatility of light, with the advantages on high resolution, high accuracy,
high sensitivity and reproducibility, it has become the primary means of the optical shape measurement. Laser
wavelength scanning interference moves the test aspheric mirror in the optical axis direction controlled by the electric
translation stage precisely, gradually changes the relative distance between the aspheric test mirror and the interferometer.
Thus the reference sphere wavefronts with different radius match automatically to different ring-zones of the aspheric
mirror. Based on the laser wavelength scanning interference testing of aspheric surface, this paper calculates the center
area and the annular area separately. In the annular area processing, the authors use Zernike polynomials to fit the phase
diagram, then derivative along the radial direction, to extract the zero-phase points on the interferogram of each relative
position, and get the angle between the normal and the aspheric axis, then rebuild the absolute position of the coordinate
system of aspheric mirror. Experimental results show that the method has high accuracy and reliability.