The coding machine is mainly composed of: hydraulic system, electrical control system, automatic dialing system and bed. The workpiece is placed on the bottom coding mold, and the piston rod of the hydraulic cylinder pushes the bottom coding mold. When it passes under the number plate, it is crushed by the number plate and the bottom coding mold, and the numbers or English letters are printed on the bottom ring. . Each time you pass the dial, the dial will automatically dial once, so that the numbers printed each time will be changed in sequence.