Abstract: A novel resin matrix carbon brush (RMCB) was prepared by dispersing sulfonated graphene oxide (SGO) and flake graphite powder into a phenolic resin alcohol solution, followed by drying, hot rolling, pulverization, cold pressing and solidification by heat treatment. The current-carrying wear performance of the RMCB was tested by using it in a heavy-duty industrial motor at different on-load voltages from 200 to 240 V for 4 h and examining it after use. The microstructure was characterized by XRD, SEM, EDS and TEM. Results show that the flake graphite particles were bridged by SGO and the ground surface of the brush exhibited an interconnected carbon structure. The wear rate of the RMCB with SGO was 2.06×10^-7 mg·N^-1·m^-1 at 220 V, which was 31.3% of that of the RMCB without SGO. The combined action of arc erosion wear, oxidative wear and adhesive wear was the dominant wear mechanism of the brush with and without SGO during the current-carrying wear test.