A novel constitutive model was developed for composite by combining the theory of macro and micro scale coupled constitutive model and the virtual displacement principle.The displacement within the subcell was expanded in terms of the global strains and the fluctuating displacements.Then the virtual displacement principle was used to construct the basic equations of the model.The periodic boundary conditions were employed to solve the basic equations.Finally the relation between global stress increment and global strain increment was deduced.Both the accuracy and efficiency of the new model were verified numerically by comparing with finite volume directe average method(FVDAM).The global elastic modulo and transverse elastic-plastic stress-strain responses were also predicted by the new model.The results show that predictions of the model are in good agreement with transformation equations and experiment.