Based on the motion relationship of abrasive and workpiece, the abrasive kinds and the crucial parameters in rough
lapping, fine lapping, rough polishing and fine polishing were established through a lot of technology experiments firstly
in this work. The exploring experiments indicate the high quality surface of SiC plane reflector can be finished in short
time. Secondly, the validation experiments were performed on the large scale SiC plane mirror with a size of 225×172
mm2. As a result, the machining flow sheet was erected. Moreover, the machining tool, abrasive kinds, abrasive size,
processing methods and testing solutions were all assembled in response to the flow sheet. The finished of 225×172 mm2
SiC plane mirror was tested and evaluated. The results show that the surface figure error, i.e. PV, is 0.0117μm, and the
surface roughness RMS is close to 0.68nm.