The invention discloses a Pb-substrate/3D-PbO2/MeOx composite anode and a preparation method thereof. The Pb-substrate/3D-PbO2/MeOx composite anode comprises a Pb substrate, 3D-PbO2 and a metal oxide film layer. The preparation method includes constructing a 3D-PbO2 structure on the surface of the Pb substrate through an electrochemical anodic oxidation method, and depositing MeOx inside the 3D-PbO2 structure through an electrochemical deposition or chemical deposition method. The Pb-substrate/3D-PbO2/MeOx composite anode and the preparation method thereof have the advantages that the 3D-PbO2 structure is capable of enlarging a contact area between the Pb substrate and the metal oxide film layer, fixing the metal oxide film layer, bearing internal pressure generated by electrolyte solution inflation and phase transformation and inhibiting cracking and peeling of the film layer, and accordingly the Pb-substrate/3D-PbO2/MeOx composite anode is higher in film layer stability and longer in service life as compared with a traditional Pb-substrate coated composite anode; the preparation method is simple in preparation technology and easy for industrialization.