The invention discloses a graphite film with thermal conductivity and a preparation method thereof. The film comprises a graphite layer, a high-molecular material layer and a nano-material layer, wherein the graphite layer is externally wrapped by the high-molecular material layer, the high-molecular material layer is externally wrapped by the nano-material layer, the thickness of the graphite layer is 0.01mm, the thickness of the high-molecular material layer is 0.005mm, and the thickness of the nano-material is 45nm; the high-molecular material layer is an intersected composite layer which comprises polyether-ether-ketone resin and glass fibre, wherein weight percentages of the polyether-ether-ketone resin and the glass fibre are 73.5% and 26.5%, thickness of the polyether-ether-ketone resin is 0.002mm, and thickness of glass fibre is 0.003mm; the nano-material layer is a composite layer comprising a nano-material and nano-ceramic, wherein weight percentages of the nano-material and the nano-ceramic are 56.8% and 26.5%. The graphite film with thermal conductivity has high thermal conductivity, and the measured thermal conductivity is 1800-2500w/m-k which is higher than the thermal conductivity of graphite films produced by a traditional production process; and the graphite film with thermal conductivity has a high output and a low production cost.