Magnetic Abrasive Finishing (MAF) is a technique to enhance the surface quality of products. In MAF, the magnetic abrasive particles (MAPs) play a vital role. In this study, the processing performance of Al2O3/Fe-based composite spherical MAPs prepared by gas atomization is studied. Experimental results indicate that different sizes of MAPs and Al2O3 grains have different finishing performance. The surface quality of 316L stainless steel is significantly improved by using 100-120 mesh MAPs with W7 Al2O3 grains. The effective processing time of MAPs can reach 155 minutes. It is normal wear in the finishing process, and there is no MAP crushing and Al2O3 grains shedding. The MAPs have good finishing performance and long wear life.