In the process of preparation of metallographic sample, pre grinding, polishing and grinding are the indispensable procedures, which are usually finished by the grinding and polishing machine. However, for some rough work pieces, they should be finished by some special machines. According to the different kinds of requirements of the customer, our company designs GPM-2-300 spectrum grinding machine, which has novel and beautiful appearance, and the whole frame adopts spray process. The machine is very easy to use and the abrasive paper is also convenient to be replaced. It saves time and avoids wasting. There is an internal dust collecting device, makes it safety and environmental protective. This machine starts steady and has large transmission power and low noise. This machine can be adapted to various materials preparation of test samples, improves the quality and efficiency of the grinding and polishing, which is the best equipment of metallographic sample preparation.