As a material with both glass and ceramic properties, glass-ceramics have been widely used because of its low expansion coefficient, stable physical and chemical properties, and good mechanical properties. In order to obtain the super-smooth surface of glass-ceramics, the bonnet polishing method was used in this paper. Firstly, the removal mechanism of glass-ceramics was analyzed, and the influence of particle size on the removal mode was obtained by establishing the indentation depth model of free abrasive particles. Secondly, the best polishing slurry formulation was obtained by investigating the dispersion of abrasive particles in polishing slurry with different kinds and contents of dispersants. Then, through the comparative experiment of glass-ceramics polishing, it was proved that the dispersion effect of abrasive particles in polishing slurry has a significant impact on the polishing quality. Finally, through orthogonal experiments, the optimal processing parameters were selected, and only the alumina abrasive particles with an average size of 2.5 μm were used to obtain a super-smooth surface with a surface roughness Ra of 3.16 nm.