The epoxy resin is widely applied in the fields of national defense and economy because of its high bonding strength to the metallic and non-metallic surface after solidification. The carbon nanomaterials, especially the ordered structures of carbon nanomaterial with excellent structure and performance, are widely used in the research of new electromagnetic protection material. The combination of epoxy resin and the ordered structure carbon nanomaterials shows obvious advantage in the aspects of electromagnetic shielding effectiveness and mechanical property. On the basis of the epoxy resin/carbon nanotube electromagnetic shielding composite materials and the ordered carbon nanotube structures’ researches, the ideal structure model with electromagnetic shielding property ≥82.96 dB in the range of 8-12 GHz is obtained through optimal design of electromagnetic simulation and structure fabrication of electrical conductivity three-dimensional network. This investigation provides guidance for researching electromagnetic shielding composite based on epoxy resin and carbon nanomaterials.