The invention discloses a method for controllably preparing a three-dimensional nanometer porous graphene powder by a chemical vapor deposition method. The method comprises the following steps of treating a solid catalyst by salt, and activating at high temperature; coating the surface of the solid powder, subjected to high-temperature activating, with a polymer, leading the solid powder, coated with the polymer, into a carbon source at high temperature, performing the chemical vapor deposition, and growing graphene; pickling, filtering, and drying, so as to obtain the three-dimensional nanometer porous graphene powder. The method has the advantages that the common core problem of particle agglomeration of a solid catalyst in a large-scale preparation process of graphene powder by the chemical vapor deposition method is solved by the surface coating of the catalyst; by adjusting the amount of the carbon source, the particle size of the solid catalyst and the amount of salt, the high-quality three-dimensional nanometer porous graphene powder can be controllably prepared; the technology process is simplified, the higher requirement preparation conditions on equipment is decreased, and the large-scale controllable preparation of the three-dimensional nanometer porous graphene powder is easy to implement.