The invention discloses a simple method of using foam nickel as a substrate to prepare a three-dimensional graphene-carbon nitrogen nanotube composite. Effective composite of three-dimensional graphene and carbon nanotubes is realized by directly growing the carbon nanotubes on the surface of the three-dimensional graphene by means of the two-step chemical vapor deposition technique, and functionalization of a carbon-based three-dimensional structure is realized by introducing nitrogen-doped atoms into the carbon nanotubes. Compared with other methods for preparing the three-dimensional graphene-carbon nitrogen nanotube composite, the method has the advantages of simplicity in preparation process, low cost, high product conductivity, large specific surface area and the like. The three-dimensional graphene-carbon nitrogen nanotube composite obtained by the method has excellent performances in terms of catalysis oxygen reduction reaction, electrochemical capacitors, electrochemical biological sensing, super-hydrophobic oleophylic foams and the like, and has high potential application values in terms of ionic cells, drug transmission, microreactors and the like.