The invention discloses a bimetal cobalt oxide-based oxide as well as a preparation method and application thereof. The general formula of the bimetal cobalt oxide-based oxide is MaCobOn, a is 0-3, bis 0-3, a and b do not include 0, n is determined by the oxidation state of other elements, M is selected from one or more of iron, nickel, manganese, zinc or copper, and the surface of the bimetal cobalt oxide-based oxide has defects. The invention also discloses a preparation method and application of the catalyst. The structure of the precursor is controlled by regulating the optimal metal ionratio of the two transition metals and changing the mixed alcohol solvent in the solvothermal reaction, and finally the MaCobOn with different active site distributions can be obtained. As an oxygen reduction catalyst, the MaCobOn has the advantages of proper defects, high activity and stable performance, and meanwhile, the introduction of M metal greatly improves the electron transfer efficiencyand realizes an efficient oxygen reduction process. The preparation process of MaCobOn is simple, the process operability is high, and MaCobOn has good application prospects in the fields of metal-airbatteries, fuel cells, electrolytic cells, super capacitors and the like.