Inkjet printer is a single-chip control, non-contact inkjet marking system. By controlling the internal gear pump or the compressed air supply from the outside of the machine, a certain pressure is applied to the ink in the system so that the ink is ejected through a few tens of micrometers of aperture. And the crystal oscillation signal which added above the nozzle will split the continuous injected ink line into droplets with the same frequency, the same size, and a certain distance. The ink droplets are charged when pass through the charging electrode, amount of its charge is controlled by the central processing unit CPU. Then they pass through the detection electrode to detect the actual charge amount and phase of the droplet is correct; finally, the charged droplets are deflected by the deflecting electrode in the deflection electric field and jet from the print head, respectively print different positions on the surface of the product, forming a variety of text, graphics and other logo. At the same time not being charged droplets run into the recovery tank, re-enter the ink circulation system inside the machine.