Abstract: A micromechanical model is developed to predict electro-magneto-thermo-elastic full-coupling behavior of smart materials based on the variational asymptotic homogenization method. Starting from the variational expression of energy functional derived from electro-magneto-thermo-elastic coupling constitutive equation of smart materials, the energy functional was asymptotically extended to a series of approximate functional by taking advantage of the small ratio of microscale to macroscale of unit cell. The fluctuation function of the field variables were obtained by minimizing the approximation functional, resulting in a micromechanical model which is as close as possible to the physical and engineering reality. This model was implemented by using finite element technology. The example results of BaTiO₃-CoFe₂O₄ fiber/epoxy resin composites show that the constructed micromechanical model can accurately predict the electro-magneto-thermo-elastic behavior and recover the local distribution of multi-physical field.