The white rice enters the polishing chamber of the polishing machine. Under the pressure to be determined and the infiltration of water mist, the surface of the rice grains is polished through friction, thereby forming a 50-20 micron thick gelatinized layer on the surface, which can not only remove the floating bran on the surface of the rice grains, but also It can also gelatinize the starch on the surface of the rice grains to make up for cracks, thereby obtaining a crystal-clear appearance and improving the storage performance and commercial value of the rice.