<p>Various factors influence the deformation and damageability of materials, including composition, structure, loading regime, and environmental conditions. Elastic and plastic deformations are the main forms of deformation, and failure is usually the result of cumulative damage. Based on the principle of thermodynamic consistency, this study presents a new model of continuous damage mechanics for fiber-reinforced composites in the form of a description of the damage evolution process. The matrix of the deformation energy release rate during damage is determined using the free energy function, and the damage stiffness matrix is obtained by combining it with the principle of deformation energy equivalence, which effectively represents changes in the mechanical properties of the material under different damage conditions. The results show that the model can accurately reflect the anisotropic elastic properties of the material and their coupling effects, significantly simplifies experimental procedures, and requires only a simple tensile test to determine key damage parameters. This model provides a reliable theoretical basis and practical value for predicting material damage, optimizing design, and evaluating performance under complex loading conditions. Moreover, future research can improve the model by enhancing its mathematical simplicity, multiscale applicability, and data-driven prediction accuracy.</p>