Aiming at the similarity between the grinding mechanism and the grinding mechanism of abrasive belt, a new high-precision polishing process scheme is proposed. Using new tape sandpaper, the grinding test is carried out by the specimen polishing machine. Research and tests have confirmed that under the action of the same grinding force, because the new tape sandpaper has soft elasticity, multiple abrasive particles, and small particle size, tight and fine arrangement, the heat generation in grinding is small, and no new deformation layer will be produced. The data of the grinding test of Cr12, a common material of mold with ordinary sandpaper and new tape sandpaper, were plotted into a curve, and analyzed and compared to show that the surface accuracy after polishing with the new tape sandpaper was improved by two to three grades compared with the ordinary polishing process, and high fine precision was achieved.