Abstract: Large hydraulic concrete structures are prone to stress concentration at points of structural discontinuity. The overall failure of engineering structures originates from damage accumulation and crack instability extension in local areas. To clarify the mechanical properties of concrete gravity dams under seismic loading, this study adopts the submodel method to construct a refined model of the high stress zone in the heel of gravity dams based on actual engineering projects. On the basis of the meso structural model of the representative element of the dam heel, the local force deformation characteristics and damage evolution process of the gravity dam under seismic action are studied. It shows that the results of the meso submodel can more realistically reflect the stress field, displacement field, crack distribution and damage evolution process than the macro model. In addition, it finds that the damage occurrence in the meso structure is earlier than in the macro structure. This indicates that the macro cracks originate from the inside, and the destruction of concrete structure is not instantaneous, but caused by the evolution of its internal microcracks to form larger macrocracks. These results provide a reference for the formation and distribution of the damage of gravity dams at macro and meso scales.