A composite article that can be used as a substrate for coated conductors is disclosed. The composite substrate has at least three layers in which one or more inner layers of Ni—W alloys with 9 at. %-13 at. % W and two outer layers of Ni—W alloys with 3 at. %-9 at. % W. The content of W element gradually decreases from the inner layers to the outer layers. The composite substrate can be prepared using a process of designing and sintering composite ingot, rolling composite ingot and then annealing composite substrate. The composite substrate have a dominant cube texture on the outer layer of the whole substrate which have a weaker magnetism and higher strength than that of a single Ni-5 at. % W alloy substrate. the preformed composite ingot is prepared by filling and compacting the Ni—W mixed powders into a mold layer by layer according to the structure of composite substrate; in said mold, said preformed composite ingots are with the total thickness of 5-250 mm, the thickness of two outer layers being 2/9-⅔ of the total thickness.