Small character inkjet machine is also known as the continuous inkjet machine, that is, CIJ inkjet machine. Its working principle is that under the action of pressure, the ink enters the spray chamber, which is equipped with a crystal oscillator. through vibration, the ink is sprayed from the nozzle with a very small aperture (generally 60 microns) to form a fixed interval point. through the charging pole, some ink points are charged with different electric nuclei, and under the high voltage magnetic field after several thousand volts, different offset occurs, and the flying nozzle falls on the surface of the moving product, forming a dot matrix, so as to form words, numbers or graphics.