The invention discloses a phase change heat conducting fin. The phase change heat conducting fin comprises a porous alumina framework. Organic phase change material is filled in holes of the porous alumina framework. The phase change heat conducting fin uses the porous alumina framework as a heat conducting framework filled with the organic phase change material inside. On the premise that the phase change heat conducting fin has high thermal conductivity, the organic phase change material fills interface gaps through phase change at lower temperature, and then greatly reduces interface thermal resistance, and thereby is an ideal thermal interface material applied to heat dissipation devices and the like. The invention further discloses a preparation method of the phase change heat conducting fin. The preparation method has the advantages of being simple in process, easy to operate, high in yield, gentle in reaction condition, low in energy consumption and the like, and is suitable for industrialized mass production. The invention further discloses a manufacturing device of the porous alumina framework. The manufacturing device of the porous alumina framework can guarantee good and stable proceeding of the electrolytic process of the porous alumina framework.