In this paper, the finite element software——ABAQUS Computing Platform is used to build two-dimension unit cell of the composite one-way slab model. Compute it by two ways: 1)supposing that the fiber and matrix are elasticity, but they are different for material parameters, and this assumption is generally used. It can be computed directly in the ABAQUS software; 2)supposing that the fiber is elasticity, but the matrix is the viscoelasticity. For the matrix, its viscoelastic character can be simulated by the solid constitutive model with three parameters. The maximum stress (MS) judgment criterion is used to determine whether the matrix is destroyed. If the matrix is destroyed, the stiffness of the whole matrix would be degraded by means of the degradation factor, which determined by the Camanho parameter degradation pattern. Compare the stress and strain curves got through the numerical simulation and through the experiments, and find that the second situation is similar to the experiment’s result.