Abstract: We studied the double-side polishing process of large-aperture ultra-thin component based on the technology of ring polishing and pendulum. The technical optimization included the speed ratio control, polishing pad shape modification and polishing particle size convergence. Computer simulation produced evidence in support of the optimization. The trouble of ultra-thin components damage in original separator was overcome by material replacement and separator thinning. We achieved the convergence of surface shape by adjusting the speed ratio on SYP152 double-side polishing machine. Through these experiments, we verified the feasibility of this processing method, the surface PV value could attain to less than 1.5(=632.8 nm) , the surface roughness could be reduced to less than 1 nm.