Abstract: The multilayer films consisting of polydimethyldiallyl ammonium chloride functionalized graphene (PDDA-GNs) and phosphomolybdate functionalized graphene (PMo₁₂-GNs) (PDDA-GNs/PMo₁₂-GNs) were fabricated on the substrate by layer-by-layer self-assembly technique. The PDDA-GNs/PMo₁₂-GNs multilayer films were used as catalyst carrier for electrodeposition of Au nanoparticles (Au/PDDA-GNs/PMo₁₂-GNs_n). The Au/PDDA-GNs/PMo₁₂-GNs_n fabricated catalyst was characterized by XRD, XPS and SEM. The results indicate that Au nanoparticles are uniformly-dispersed on the PDDA-GNs/PMo₁₂-GNs_n multilayer films. Cyclic voltammetry (CV), chronoamperometry (It) and electrochemical impedance spectra (EIS) analyses show that the Au/PDDA-GNs/PMo₁₂-GNs_n has high electrocatalytic activity and stability regarding hydrazine oxidation. Compared with Au/glassy carbon electrode (GCE), the hydrazine oxidation current density of Au/PDDA-GNs/PMo₁₂-GNs_n increases from 0.46 mA/cm² to 0.87 mA/cm². And the steady current density of the Au/PDDA-GNs/PMo₁₂-GNs_n catalyst is 2.5 times as high as the Au/GCE catalyst.