Chemical-mechanical polishing is a commonly adopted technique for the fabrication of super-smooth monocrystalline silicon mirror. Rogue particles during chemical-mechanical polishing process always result in scratches on mirror surface hence reduce surface quality. To systematically study the relationship between impurities in polishing slurry and plastic scratches on monocrystalline silicon surface with different crystal orientations, experiments on polishing Si(111), Si(110) and Si(100) surface by using diamond doped polishing slurries are designed. Scratch morphologies under different crystal orientations and different doping concentrations are measured by profilometer, and evaluated by calculating scratch width distribution, scratch depth distribution, roughness degree, surface roughness and two-dimensional power spectral density after load normalization. Results show that the size of rogue particles in the polishing slurry and the width of scratches on silicon surface obey the normal distribution. With the increase of rogue particle concentration, the scratch morphology changes from non-periodic characteristics to periodic fluctuations, and the roughness shows a jump point. In addition, in the case of the same diamond doping concentration, Si(110) has better tolerance of rogue particles at the initial stage of scratch generation.