Disclosed are a metal wire, a manufacturing method therefor, and a tire. The metal wire is manufactured by twisting monofilaments; an outer peripheral surface of each monofilament is covered with a Cu-M-Zn alloy coating; the outer peripheral surface of each monofilament is further covered with a Cu-Zn alloy coating; there is at least one monofilament from which the metal wire is made; a coverage area of the Cu-M-Zn alloy coating is 10-90% of the area of the outer peripheral surface of each monofilament, and the rest is the Cu-Zn alloy coating; M in the Cu-M-Zn alloy coating is selected from one or two of cobalt, nickel, manganese, and molybdenum; the mass fraction of copper in the Cu-M-Zn alloy coating is 58-72%, the mass fraction of M in the Cu-M-Zn alloy coating is 0.5-5%, and the balance in the Cu-M-Zn alloy coating is zinc and inevitable impurities. The present invention has the beneficial effects that the metal wire is good in both initial adhesion and damp-heat aging adhesion, and is particularly applicable to a cobalt-free rubber component because each monofilament that forms the metal wire is provided with two kinds of alloy coatings at the same time.