In order to study the performance of abrasive flow polishing on the micro-holes, the polishing process of abrasive flow with different abrasive particle sizes was carried out by using computational fluid dynamics. The distribution of fluid turbulence intensity and abrasive particle velocity, fluid turbulence dissipation rate and kinetic energy of abrasive particles were obtained and analyzed. The simulation reveal that the material removal rate is proportional to the size of abrasive particle size, while the surface quality is inversely proportional to it. Therefore, the appropriate size of abrasive particle should be selected according to the initial surface roughness of the workpiece. The research results have certain guiding significance for practical production.