A method for preparing a three-dimensional porous graphene material, including: a) constructing a CAD model corresponding to a required three-dimensional porous structure, and designing an external shape and internal structure parameters of the model; b) based on the CAD model, preparing a three-dimensional porous metal structure using a metal powder as material; c) heating the three-dimensional porous metal structure and preparing a metal template of the required three-dimensional porous structure; d) placing the metal template in a tube furnace and heating the metal template to a temperature of between 800 and 1000° C.; standing for 0.5-1 hr, introducing a carbon source to the tube furnace for continued reaction, cooling resulting products to room temperature to yield a three-dimensional graphene grown on the metal template; and e) preparing a corrosive solution, and immersing the three-dimensional graphene in the corrosive solution.