Abstract: According to the autoclave forming process of thermoset resin composites, a three-dimensional model which uses the generalized Maxwell viscoelastic constitutive model was established to calculate the residual stress and curing deformation. Thermo-chemical behavior, thermal expansion and contraction behavior, viscoelastic behavior and anisotropy were fully considered in the model. According to the comparison with experiment data in reference, the model established is proved to have relative superior reliability. The curing process of C-shaped composite structure was numerical simulated and compared with experimental data, and the results show high precision of the numerical model in predicting the curing deformation.