Considering the defect into fiber bundle and outer matrix,a multiscale unit-cell model is establiashed.At first,according to the scanning electron microscope(SEM) photograph and the density into the material,the geometric dimensioning of the unit-cell of fiber bundle and composite is confirmed.Then,introducing into the periodic boundary condition,the initial modulus and strength are calculated by using the fiber bundle unit-cell containing defects.At last,using the composite unit-cell model which confirming geometric dimensioning by SEM photograph,the stiffness is predicted by the material parameters from previous scale.The stiffness matrix of the damaged unit-cell for fiber bundle was established.The damage evolvement method by introducing damage variables of different damage modes were considered as the progressive damage of the material integral points.It was analyzed and discussed by comparing numerical predictions with experimental data.And the damaged material properties under uniaxial load are given at last.The results indicate that numerical simulation of the nonlinear stress-strain behavior based on Hashin failure criteria with various damage modes gives good agreement compared to experimental results.