Uni-axial compression test was used to analyze characteristics of stress-strain curves and effects of porosity on mechanical properties and deformations of the Fe-40at%Al intermetallic compound porous material, which was prepared by the element mixture partial diffusion - reactive synthesis – sintering method. Its microscopic fracture mechanism were revealed by scanning electron microscope test. Research results show that the compressive stress-strain curves of the FeAl porous material with different porosities can be divided into four stages: elasticity, yielding, strengthening and failure, where the larger the porosity (i.e., the lower the relative density), the more obvious the nonlinear elasticity. As the porosity is increased, the yield strength is almost unchanged, while the compressive strength and elastic modulus are decrease greatly. Its characteristic of the fracture surface is of brittle fracture in macroscopy and of intergranular fracture in microscopy. Compared with the theoretical values and experimental values of the elastic modulus of FeAl porous material,the micromechanics model of heterogeneous Plateau porous structure is more accurate for predicting the effective elastic modulus of the medium-density porous material but not for high-density porous materials.