A graphene material prepared using waste tires and a preparation method thereof. Waste tires are crushed to 30-200 meshes to obtain tire powders. The tire powders are mixed with KOH or an aqueous solution of KOH to obtain a homogeneous mixture. The mixture is dried at 50-90° C. for 12-48 hours, heated and calcinated in a tube furnace under a protective gas for 1-48 hour to obtain a black lump. The black lump is washed with distilled water, dilute hydrochloric acid or dilute sulfuric acid for at least 3 times, and then washed with deionized water for at least 3 times to obtain a black powder. The black powder is dried to obtain the graphene material. The graphene material has a three-dimensional structure composed of oligolayer graphene intertwined and connected with each other, has a high crystallinity, is not easily agglomerated, and thus can maintain nano-effect of the graphene material.