The introduction of hydrogen energy can effectively improve the power supply reliability of the distribution network, and hydrogen production from water electrolysis is a key technology to achieve low-carbon transformation, so it is imperative to develop efficient electrolysis water catalysts. Transition metal oxides have large reserves and high catalytic activity, and are regarded as promising oxygen evolution reaction catalysts. In this work, the oxygen evolution catalyst of graphene which supports Co3O4 was prepared by radio frequency plasma. The test results of XRD, Raman and XPS show that the introduction of two-dimensional graphene accelerates the surface electron migration and increases the reaction area. Plasma treatment facilitates the loading of nanoparticle on graphene, and plasma etching is used on the surface of catalyst to create a large number of graphene structural defects and oxygen vacancies, which improves the distribution of active sites, effectively regulates the electronic structure of Co3O4 and improves the catalytic activity of oxygen evolution. Electrochemical tests show that the overpotential of Co3O4@rGO synthesized in this experiment is 410 mV at a current density of 50 mA·cm-2, the kinetic reaction rate is fast, and exhibits a catalytic activity of oxygen evolution that is superior to that of commercial IrO2.