The half-through arch bridge, known for its efficient structural design and seamless integration with the surrounding environment, is widely utilized in urban transportation infrastructure. However, during operation, the hangers of the through and half-through arch bridge are exposed to various factors, including environmental conditions and cyclic traffic loads, which often cause the hanger of these bridges to rust and fracture, will lead to structural damage or even the collapse of the entire bridge. Therefore, investigating the dynamic performance of half-through arch bridges, both before and after hanger damage, under vehicle-bridge coupling is of paramount importance for understanding the overall performance of the bridge. In this study, a half-through arch bridge was selected as the subject of investigation. A three-dimensional finite element model of the bridge was developed based on real-world engineering projects, and a numerical simulation of the vehicle-bridge coupling system was created using vehicle-bridge coupling vibration theory. This model enabled a comprehensive analysis of the dynamic deflection variations at the hangers and beam anchorage points under vehicle-bridge coupling, and assessed the impact of hanger damage on the bridge's dynamic response. The results show that the dynamic response of the corresponding anchor points of the hangers at different positions varies significantly under different damage levels. When a short hanger fractures, the dynamic deflection at the beam anchor point increases dramatically compared to the undamaged state, showing a clear nonlinear relationship between the hanger damage level and the dynamic deflection at the anchor point. In the case of long hangers, secondary fitting more effectively illustrates the correlation between the damage level and the maximum dynamic deflection at the anchor point.