You can polish the mold with an oilstone or an ultrasonic polisher. When polishing with oilstone, you should first polish with coarse oilstone, then polish with fine oilstone, and finally polish with fine oilstone. Then use fine sandpaper to polish, and finally use metallographic sandpaper to polish. When polishing with ultrasonic polishing machine, it is also necessary to polish with coarse oilstone to remove the tool marks left by mechanical processing, and then polish off the grinding marks of coarse oilstone in front with fine oilstone. Then the polishing machine was replaced, and polishing paste was coated on the polishing tool to polish the mold cavity. Similarly, it is polished with coarse polishing paste first, then with fine polishing paste, and finally with W3.5 polishing paste.