A page-width array printing device includes a page-width array printing mechanism including at least one page-width array printing module. The page-width array printing module includes a printing platform, a first page-width array printing unit and a second page-width array printing unit. The first page-width array printing unit includes a plurality of first inkjet cartridges. The second page-width array printing unit includes a plurality of second inkjet cartridges. The first page-width array printing unit and the second page-width array printing unit are in parallel with each other. The first inkjet cartridges and the second inkjet cartridges are staggered and independently and detachably disposed on the printing platform. Each of the first inkjet cartridges and the second inkjet cartridges includes an inkjet chip. The inkjet chip includes four ink supply channels and a plurality of nozzles so as to perform a monochromatic or polychromatic page-width array printing operation.