Abstract: The invention belongs to the technical field of catalytic material preparation, and provides a method for graphitization of diamond film surface. High-current pulsed electron beam is used to bombard the diamond surface, and the microscopic area bombarded by the high-current pulsed electron beam can meet the thermodynamic and dynamic conditions for transforming diamond into graphite under high-temperature and low-pressure environment, so that graphitization only occurs on the diamond surface. Specifically, the substrate for cleaning and removing the surface oxide layer is placed in diamond powder suspension for ultrasonic treatment, and then placed on a sample table in a hot filament chemical vapor deposition device for fine purification and activation treatment; The substrate on which the diamond film is deposited is fixed on the clamping device inside the high current pulsed electron beam device to obtain graphitized diamond film on the surface. The high-current pulsed electron beam of the invention has high energy density, and the high temperature and low pressure conditions in the micro area are more conducive to the transformation of diamond to graphitization, thus forming a cathode catalyst with good thermal conductivity, electrical conductivity and oxygen reduction catalytic activity at the same time.