Preparation method of low expansion graphite

The invention relates to the technical field of a graphite negative electrode material, in particular to a preparation method of low expansion graphite. The preparation method is characterized by comprising the following steps of (1) smashing and shaping flake graphite raw material to grain sizes with D50 being 5-10 micrometers; (2) mixing the flake graphite raw material, an adhesive easy to be graphitized and a graphitized catalyst; (3) performing low-temperature thermal processing for 10-20 hours at 300-800 DEG C under protection of inert gas, and cooling the mixture to a room temperature; (4) performing catalytic graphitization high-temperature processing for 24-48 hours at 2,800-3,200 DEG C under the protection of inert gas; and (5) sieving the mixture, and obtaining the low expansion graphite. Compared with the prior art, the preparation method is simple and practical and is suitably used for industrial production, the prepared graphite is low in expansion, large in discharge capacity and high in cycle p