▎ 摘　　要

NOVELTY - Preparing carbon-based composite filler comprises (i) performing surface hydroxylation treatment on carbon films by three-electrode cyclic voltammetry; separating the carbon film, washing the carbon film with deionized water, and drying to obtain hydroxylated carbon film; (ii) soaking the hydroxylated carbon film in saturated metal salt solution, taking out the carbon film after soaking for 6-12 hours, drying to obtain metal salt-loaded carbon film; the saturated metal salt solution contains aluminum sulfate, zinc chloride and/or magnesium chloride; and (iii) heating the metal salt-loaded carbon film with 30-60V direct current in oxygen atmosphere for 150-500 ms to obtain carbon-based composite filler; or heating the metal salt-loaded carbon film with 30-60V direct current under atmosphere of inert protective gas for 150-500 ms, turning off power, introducing oxygen to convert metal salts into metal oxides to obtain carbon-based composite filler. USE - The carbon-based composite filler is useful for thermal interface material used in LED packaging (all claimed). ADVANTAGE - The carbon-based composite filler: has high thermal conductivity. The thermal interface material: has high thermal conductivity, high insulation and low water absorption, and is especially suitable for use as LED packaging material DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) carbon-based composite filler is prepared by above mentioned method; and (2) Thermal interface material, which is prepared from epoxy resin, active diluent and filler, filler is prepared by above mentioned method, the filler accounts for 0.5-5 wt.% of the total mass of the thermal interface material preparation raw materials.