The invention discloses a technology method for improving surface dielectric medium performance of epoxy resin insulation tools and appliances, and belongs to the technical field of electric power. The method comprises the steps that a reaction chamber is subjected to vacuum pumping; fluorine gas is injected into the reaction chamber; and gas-phase fluoridation treatment is conducted on the epoxy resin in the reaction chamber. By means of the shown technology method, chemical compositions and structures of epoxy resin on the insulation tools and appliances can be changed while any body compositions, structures and characters of the epoxy resin are not changed, the restraining effect on epoxy resin surface charge accumulation can be improved, accordingly, charges cannot be stored in an epoxy resin surface layer, accordingly, the damp proofness and surface ageing resistance of the insulation tools and appliances are improved, and the service life of the insulation tools and appliances is prolonged.