The 3DG powder is prepared via the chemical vapor deposition method. It features spherical particles with particle sizes ranging from 200 to 400 nm. The graphene sheets grow along the radial direction of the particles and form a three-dimensional structure by bonding to each other. The internal part of the graphene sheet features a multi-layer structure while its edge section comprises 1 to 2 layers. The graphene sheets in each 3DG particle are well separated from each other. The edges are completely exposed. They are of high reactivity and will not agglomerate during usage. As the 3DG powder was directly grown under high temperature, the 3DG powder has good crystallinity and high electrical conductivity. Its applications include conductive agent in lithium ion batteries, conductive agent in supercapacitors, carbon coated copper/aluminum foil, anti-corrosion paints, hard anti-abrasion coatings, conductive coatings, thermal conductive coatings, filling agent materials for electrically conductive/thermal conductive/electromagnetic shielding/high strength composites.