Abstract: Establishing a constitutive model for granular materials that accounts for particle shape and breakage mechanisms has been crucial for calculating the mechanical stability of earth-rock dam projects. Initially, the impact of particle breakage, rotation, and sliding on the deformation of granular materials with varying shapes had been examined. Subsequently, based on geotechnical damage mechanics and thermodynamics, mathematical expressions for particle crushing energy and dilatancy energy that consider particle shape were developed. By incorporating the particle breakage rate equation, the evolution of particle crushing energy, dilatancy energy, and breakage degree during compression was elucidated, quantitatively revealing the meso-particle breakage deformation mechanism. These mathematical relationships of meso-deformation mechanisms were then integrated into the existing D-C model, resulting in an elastoplastic constitutive model that considers both particle shape and meso-particle breakage mechanisms. The model's validity and reliability were confirmed by comparing experimental curves with theoretical predictions.