The issue of the letter is focused on the RB-SiC aspherical mirror high frequency surface quality which is fabricated with the different type fixed abrasive pellets. The two-dimensional (2D) surface roughness of the mirror is simulated and experimented. The errors between the simulation and the experiment are 5.97%, 3.19%, 3.59%, 37.37% using W1.5, W3.5, W5, W7 pellets respectively. The error emerging reason is analyzed in detail after the comparison. Also the fractal theory is applied on the analysis of the optical mirror surface fabricated with the fixed abrasive technology. The analysis result shows that the good surface quality of the RB-SiC mirror can be obtained quickly with being polished with the fixed abrasive technology. So the fixed abrasive technology is very suitable for the fast optical surfacing, especially can obtain good surface roughness fast in the stage of grinding mirror which is not suitable for being tested with interferometer.