The invention discloses a 3D printing preparation method for a high-strength titanium alloy part of a porous structure, and belongs to the field of 3D printing material design and preparation. The method is characterized in that the titanium alloy part of the porous structure is formed by superposing a plurality of rhombic dodecahedron basic units, the interiors of the basic units are hollowed out, four reinforcing supports are arranged in the body diagonal direction, each metal frame is formed by adopting a laser 3D printing technology, and every two adjacent basic units share one surface. The method has the advantages that the pore size of the porous material obtained through the method is small, and the porosity can be controlled by regulating and controlling the dimension parameters ofthe basic units; and the yield strength and the torsional strength of a product are higher than those of a conventional 3D printing porous material under the condition of the same porosity.