The invention provides a long-service-life copper-molybdenum etching solution. The etching solution contains an etching solution mother liquid and an etching solution child liquid, wherein the etchingsolution mother liquid mainly contains hydrogen peroxide, a regulator, a stabilizer, organic acid, an inhibitor, a pH regulator and the balance of water; and the etching solution child liquid mainlycontains a dissolving agent, organic acid, an inhibitor and a stabilizer. The invention further provides an etching method of a copper-molybdenum metal film. The etching solution and the etching method have the beneficial effects that by adding a composition of the dissolving agent, organic acid, the inhibitor and the stabilizer into the etching solution with a certain copper ion concentration, the service life of the etching solution is further prolonged, and the stability of the etching quality is further improved.