In order to realize testing of a large aperture SiC convex asphere
aberration free testing method and compensator tesing method are analyzed. After majorized comparison
null lens testing method is selected. Offner null lens for large SiC Convex asphere are designed.The design results indicate that the precision of the system’s is PV:0.0082,RMS:0.0029(=0.6328nm), large aperture zygo interferometer is used and convergent testing method is adapted . The final testing results or the mirror is 0.022(RMS). Th e design method is universal and the design results can be used in the compensator design for other convex SiC mirror.The testing result of convex asphere is improved
the selection of the material and supporting structure etc. is majorized
it give more chance for new style of convex asphere mirror.