In order to improve the thermal conductivity of the interfacial materials,different processes were adopted to study the thermal conductive alumina fillers for interfacial materials.The effect of morphology,adding amount and proportion of the thermal conductive alumina fillers on the thermal conductivity of the interface materials were investigated,and the optimum cost perfor-mance ratio formula and modification process of thermal conductive alumina filler were selected.The experimental results showed that when the thermally conductive alumina filler for the interface material was compounded in a mass ratio of 2∶3∶2 in 45 μm spherical,45 μm like-spherical and 5 μm angular shapes and undergoes a combined dry-wet modification,the adding amount can reach 95%（accounting for the mass fraction of the silicone oil system）,and the thermal conductivity can reach 4.25 W/（m·K）.