Surface　charge　accumulation　phenomena　greatly　restrict　the　development　of　DC　power　equipment.　Suppressing　surface　charges　are　of　great　significance　to　promote　surface　insulation　strength　of　polymeric　dielectrics.　In　this　study,　we　report　surface　charge　and　flashover　regulation　on　alumina/epoxy　spacers　by　graded　conductivity　coatings　under　DC　voltages.　The　spacer　surface　is　divided　into　different　circular-ring　areas　from　high　voltage　(HV)　to　grounded　(GND)　electrode.　High　conductive　coatings　consisting　of　titania　particles　of　different　contents　and　epoxy　matrix　are　fabricated　to　spray　on　different　circular-ring　areas　of　spacer　surface,　which　forms　graded　distribution　of　conductivity.　Surface　charge　distribution　on　epoxy-based　spacers　is　obtained　by　a　Kelvin　electrostatic　probe　after　DC　charging.　Flashover　voltage　is　measured　in　0.1MPa　15%SF6/85%Nmixtures.　The　results　show　that　graded　conductivity　coating　can　achieve　excellent　control　of　surface　charge　accumulation,　and　therefore　improve　flashover　performance.　©　2020　IEEE.