Polishing agent is abrasive plus media, media may be water, oil, alcohols and other substances, with different additives, the abrasive will be dispersed in the media, and then with polishing cloth to achieve the purpose of grinding and polishing, first of all, to understand the types of commonly used abrasives in general, said to be divided into two categories, one for the superabrasives and the other for the general abrasives, superabrasives, there are only two kinds of abrasives, including diamond and cubic boron nitride, general abrasives commonly found in silicon carbide (i.e. emery, aluminum oxide (i.e. corundum, zirconia, silicon oxide, etc.), in the grinding media and often will be used in the grinding media. Cubic boron nitride, general abrasives commonly found in silicon carbide (i.e. emery), aluminum oxide (i.e. corundum), zirconia, silicon oxide, etc., in the abrasive media and often add some acids and alkalis to achieve the effect of corrosion polishing, such as polishing stone or stainless steel will be added to the abrasive agent with a little acid (e.g. hydrochloric acid), polishing ceramics or silicon-carbide materials will be added to alkaline solution (e.g. potassium permanganate), and will even add peroxides and other process methods in the media. Adding hydrogen peroxide and other process methods to soften and activate the surface of the workpiece to achieve the effect of increasing the polishing rate and improving the surface of the workpiece, but also because of these factors, so the choice of polishing cloth is very important, different types of polishing cloth have different acid and alkali resistance, but also have different porosity and water absorption, to be able to adsorb different sizes of abrasive particles, in order to achieve optimal efficiency of grinding and polishing, such as coarse polishing is suitable for For example, in rough polishing, it is suitable to use foaming material with coarse porosity, or choose polishing cloth with a little hardness to achieve the purpose of quick removal, in medium polishing, the main purpose is to remove the traces of rough polishing and leave uniform grinding and polishing marks on the surface of the workpiece, it is suitable to use weaving with a little hardness to achieve the required surface effect, and in the final polishing, it is required to be free of traces, and do not allow the appearance of any small micro-scratches that should not appear, because Any micro-scratch will cause the whole process to be ruined, then we should choose the material with higher water content and oil content, and with porous long or short pile, because this can have enough lubrication will not be generated because of the heat generated during the grinding and polishing, resulting in dry polishing phenomenon, leading to abrasive agglomeration, and finally cause the most unwanted micro-scratch to occur. The following is a list of commonly used abrasives and suggestions for matching abrasives with polishing cloths.