The present invention relates to an inkjet printing apparatus, includes at least four same-typed print heads, among which, at least two eject ink for coating layer, the rest for colored inks; print heads printing coating layer are interpolated or arranged abreast in a row, and those for colored inks are ranked abreast in another; along printing medium's motion direction, nozzles of print heads ejecting the same colored ink are connected in series. Arranging or interpolating print heads ejecting ink for coating layer in a row and print heads ejecting colored inks arranged abreast in another to make whole printing area covered by coating layer in the present invention, greatly narrow width of print head baseplate, reduce demands on width of UV solidification devices, save cost, and improve operating stability of carriage.