Abstract: The anisotropy produced by the different properties of fluid and solid phase in saturated rock and soil-like porous materials and heterogeneity of porous microstructures made the calculation of micro mechanics properties very complex. In order to accurately predict the effective elastic properties and micro stress-strain fields of rock and soil-like materials, the energy functional and corresponding porous elastic constitutive relations were built based on the Biot porous elastic media theory. The energy variational functional is then asymptotically expended to series of approximate functional by taking advantage of the small ratio of micro scale to macro scale. With the fluctuation functions of field variables as unknown variables, the analytical solutions to the fluctuation functions can be obtained by solving the minimum problem(stationary value problem) of approximate functionals. Thus, a micromechanical model is established, which is as close as possible to the real physical and engineering problem. The developed micromechanical model is numerically implemented through the finite element technology. The examples of porous material show that the accuracy of micromechanical properties calculated by the developed model is much better than the classical homogenization theory, in which the fluid material is regarded as solid material with high Poisson's ratio; especially the local stress-strain fields distribution can be accurately recovered, laying a solid foundation for the analysis of damage and local fracture.