Reconstructing the inner structure of rocks has been one of the critical problems in the field of experimental rock mechanics. In this paper, natural sandstone specimens were selected as research objects, and CT scanning and two different kinds of three-dimensional (3D) printing methods were adopted to reconstruct 3D-printed specimens. It turns out that the structures of 3D-printed specimens were in proximity to natural sandstone specimens. Uniaxial compression tests and Brazilian tests were carried out on these two kinds of specimens to obtain mechanical properties. Then the strength and deformation law of natural sandstone specimens and two kinds of 3D-printed specimens were compared. The results indicated that specimens made by different methods of 3D printing technology could highly reconstruct the complex inner structure of natural sandstone specimens. In the meantime, physical and mechanical properties of 3D-printed specimens were closer to natural sandstone specimens, and the dispersion of experimental results was relatively small. Therefore, this study provides a new promising way that can conduct experimental research, produce substitutes for materials and verify numerical simulation results.