3DG fiber was prepared by growing vertical graphene sheets on the surface of electrospun nano carbon fiber via the chemical vapor deposition method. From the perspective of the fiber structure, graphene sheets grow along the radial direction of the fiber. The gaps among the graphene sheets in the array are generally under 100 nm. The height of the graphene sheets reaches high up to several hundred nanometers. Their edges are closely attached to the surface of the carbon fiber, which forms an ideal structure of 3DG. It has application value in various fields, such as electrode in electrochemistry, catalyst carrier, current collector in batteries/supercapacitors, composite materials with electrically conductive/thermal conductive/high strength properties, Li/Na/S carrier, flexible conductor, electromagnetic shielding, sound absorption, energy storage, catalysis, adsorption and purification, etc.