The invention discloses a method for obtaining the geometrical and mechanical parameters of rock samples and a holographic scanning system thereof, wherein the system includes an observation mechanism, a multi-scale penetration mechanism, a grinding mechanism, a rock sample installation mechanism arranged on a three-axis precision motion platform, and an industrial computer controlling the operation mode of each mechanism of the platform Indentation/rotary penetration test, pulse echo signal acquisition, three-dimensional surface topography reconstruction, layer by layer grinding and repeated experiments are carried out. The geometric parameters and corresponding mechanical field parameters are obtained by spatial interpolation of the three-dimensional parameter lattice accumulated by several layers of single-layer rock parameters. The holographic scanning system and method can obtain the real spatial distribution of various media in rock samples. Combined with high performance numerical calculation method, it provides a more scientific method for the analysis of rock mechanical properties, failure and instability.