The present invention relates to a method for preparing a graphite powder composite supported by transition metal particles for storing hydrogen, and more specifically, to a method for preparing a graphite powder composite supported by transition metal particles having significantly improved hydrogen storage capacity, by means of introducing the transition metal particles having support capacity and particle diameters which are controlled, of transition metals such as nickel (Ni), palladium (Pd), platinum (Pt), and yttrium (Y), to an oxidized graphite powder that is provided with functionality through a chemical surface treatment.