This paper presents an advanced magnetic polishing process that utilizes SiO2 abrasives and Fe3O4 magnetic particles within the Halbach array technique, specifically designed to enhance surface finishing efficiency while preventing material damage. The implementation of the Halbach array optimizes the influence of the magnetic field on the polishing slurry, significantly improving material removal rates and surface quality. A key innovation of this process is the integrated slurry transport system, which ensures the continuous regeneration of both abrasives and magnetic particles, thereby maintaining process stability and enhancing polishing efficiency. A detailed analysis of the Halbach array's characteristics is conducted through finite element simulations, enabling the evaluation of its optimal interactions with the abrasive particles. The experimental setup is specifically developed for trials on polymethyl methacrylate (PMMA), validating the efficacy of the proposed method. Additionally, the effects of critical process parameters, including conveyor speed, slurry flow rate, and working gap, on surface quality and material removal rate are thoroughly examined and discussed. Experimental results confirm that the proposed process achieves a nanometer-scale surface finish on PMMA while preventing surface damage, effectively reducing surface roughness from 225.146 to 0.932 nm, without the need for intermediate processing steps.