The graphene oxide hydrosol was prepared by modification of the Hummer method. The palladium chloride was taken as the raw material to prepare palladium nitrate. By stiring，a uniformity and stable hydrosol was formed by mixing the graphene oxide hydrosol and palladium nitrate. Pd nanoparticles supported on the rGO were successfully synthesized after the process of freezing-drying and reducing by NaBH4. The morphology and structure of Pd/RGO nanohybrids were characterized by SEM and XRD. The electrocatalytic property for methanol oxidation and electrochemical stability was characterized by CV and CA. Compared with the Pd/rGO prepared by co-reduction，Pd/rGO prepared by sol-gel method has better electrocatalytic activity and electrochemical stability. After exploring the reaction conditions，the optimizing reaction conditions of preparation of Pd/rGO composites was：palladium mass fraction of 40%，urea dose of 100 mg.