Abstract: The main aim of this paper is to get a quantitative relationship between the microstructure and macro effective elastic modulus by using a generalized self-consistent model, and to establish a micro-damage model for the refractory under uniaxial compression load. Hence, a uniaxial compression experiment is firstly set up to analyze the Micro-damage mechanism of the refractory. Then, a damage function about external load based on the elastic modulus of the matrix is constructed to characterize the micro-damage evolution. After that, a stress-strain curve is simulated to describe the nonlinear mechanical behavior of the refractory. A numerical simulation of MgO-C refractory under compression is finally performed with a micro-damage model. The result demonstrates that the simulated stress-strain curve is in a good agreement with the experimental result.