A multi-purpose water filter cartridge assembly has two sets of manifold holes formed in a top of a manifold integration board. Each set of manifold holes is composed of an inlet, a first outlet and a second outlet. The first outlet of the first set of manifold holes communicates with the inlet of the second set of manifold holes. The manifold integration board further has four sets of cartridge connection holes formed in a bottom thereof and each set is composed of a first inlet, a second inlet and an outlet. The first and second inlets of two sets of the four sets of cartridge connection holes respectively communicate with the first and second outlets of the first set of manifold holes. The inlets of the two sets of cartridge connection holes respectively communicate with the outlets of the first set of manifold holes. The first and second inlets of the other two sets of cartridge connection holes respectively communicate with the first and second outlets of the second set of manifold holes, and the inlets of the two sets of cartridge connection holes respectively communicate with the outlets of the second set of manifold holes through connection holes inside the manifold integration board. At least one filter cartridge is mounted on a bottom of the manifold integration board. The present invention can conveniently and accurately connect multiple filter cartridges in serial, in parallel or both.