The invention relates to a dual-interlayer symmetrical multi-pyramid configuration three-dimensional integrally-braid lattice composite material and a preparation method thereof. The composite material comprises an upper panel layer, a middle panel layer, a lower panel layer and lattice core layers arranged between the upper panel layer and the middle panel layer as well as between the middle panel layer and the lower panel layer. The composite material is characterized in that the upper panel layer, the middle panel layer and the lower panel layer form a dual-interlayer structure, the lattice core layers are of a space network truss structure consisting of symmetrical multi-pyramid configuration unit cells arranged periodically and communicated through holes, and the lattice core layers, the upper panel layer, the middle panel layer and the lower panel layer are weaved, alternated, wound and sutured into a whole according to the design rule and are subjected to once resin injection forming by adopting a resin transfer process. The preparation method in the invention comprises the steps of: 1, preparing the upper panel layer, the middle panel layer and the lower panel layer; 2, drilling a needle hole; 3, preparing the lattice core layers; and 4, curing and forming resins. The composite material prepared by the method has better integrity, more excellent mechanical property, lighter mass, higher bearing efficiency and better functionality in comparison with the traditional interlayer structure composite material.