The work aims to improve material removal rate and surface quality of K9 optical glass after abrasive finishing. The glass surface was processed in improved magnetic grinding process. Mode of relative motion was changed so that workbench could rotate along with toolhead during magnetic abrasive finishing. With material removal rate and surface quality as research objectives, the effects of main process parameters were studied for magnetic abrasive finishing. Key parameters such as toolhead rotation speed, grinding pressure, workbench speed, abrasive size were selected, and a series of experiments were done. Micro morphology under different processing conditions was observed with KEYENCE VK series shape measurement laser microscope, and the influence of main processing parameters on surface quality was analyzed. The glass was weighed with JJ124BC double electronic analytical balance before and after the processing, and material removal rate was calculated. Provided with the experiment equipment, surface roughness Ra of processed sample was 120 nm when the toolhead rotation speed was 1500 r/min, workbench speed was 200 r/min, machining gap was 2 mm, and abrasive mesh quantity was 150. According to 3D microstructure, better surface quality could be obtained provided with this group of parameters, surface consistency was better, and the highest point was 2.8 μm. For the improved magnetic abrasive finishing, grinding speed and grinding pressure are still the key processing factors, and processing experiment of K9 optical glass provide some references for processing hard brittle materials.