Abstract: Dam safety has always been a critical concern in hydraulic engineering. Investigating the ultimate bearing capacity of dam structures and conducting safety assessments provide valuable guidance for engineering design and maintenance. This study examines a roller-compacted concrete gravity dam, employing the head overload method, unit weight overload method, and strength reduction method for finite element simulations. The ultimate bearing capacity is evaluated, and the safety factor is determined. The results reveal that the head overload method is more sensitive in assessing the ultimate bearing capacity of roller-compacted concrete gravity dams. However, the strength reduction method should be prioritized in practical engineering applications for determining the safety factor, as it yields more accurate values. This study systematically elucidates the failure mechanisms of the dam model under the three evaluation methods and highlights the accuracy of the strength reduction method in determining the ultimate bearing capacity of gravity dams in real-world scenarios. These findings provide a reference for simulation-based evaluations of ultimate bearing capacity in other engineering projects.