Gas-quenched steel slag abrasive was obtained by gas quenching with high-temperature liquid steel slag as raw material. The phase composition, thermal properties, micromorphology, magnetic properties, and mechanical properties of the par-ticles were characterized by using an X-ray diffractometer, a differential thermal analyzer, a scanning electron microscope, a magnetic property meter, and a compressive strength tester, respectively. Results show that the gas-quenched steel slag abrasive is a monodisperse regular sphere. The compressive strength of a single particle is 34 N. The product is ferromag-netic and has good thermal properties. The micromorphology and flatness of the workpiece before and after grinding with the gas-quenched steel slag abrasive were measured using a three-dimensional profilometer. Results reveal that the surface roughness of the workpiece is reduced to 1.526, 0.623, and 0.227 μm after grinding for 5, 10, and 20 min, respectively. The surface profile fluctuation decreases to ± 1.0 μm. Thus, the workpiece surface tends to be flat without obvious scratches.