RB-SiC is as an ideal material for manufacturing large space mirrors owing to its excellent properties such as low density， high thermal conductivity， and good thermal stability. However， it is easy to introduce processing damage during the precision machining of its formed surface. Therefore， flexible scribing experiments were conducted to investigate the effect of flexible grinding process with abrasive belts on the material. A comparative experiment using RB-SiC with rigid/flexible contact was conducted， and the average sub-surface injury ratio of flexibility and the rigid scribing was found to be 0.677 and 0.823， respectively. Based on this， the orthogonal scribing experiments with different normal pressure， abrasive angle， and scribing speed were performed. The results showed that the influence of normal pressure and abrasive angle on material damage was more significant. Meanwhile， with the increase in normal pressure， decrease in abrasive angle， and increase in scribing speed， the degree of material damage became larger. Finally， by examining the scribing with multiple diamond abrasive grains， it was concluded that compared with the scribing of single diamond abrasive grains， the surface of the material is not severely broken or damaged， and the depth of the subsurface damage layer was less than 10 μm. This study will provide basic guidance for the flexible grinding of abrasive belts for RB-SiC.