Abstract: The bridge approach and expansion joint are often damaged in old bridges. The paper focuses on considering the vibration of bridge affected by the vehicle bumping caused by differential settlement at the joint. The approach state is divided into five grades according to the settlement at the abutment. Based on the five parameters vehicle-bridge coupled model, the vibration equation is deduced and Newmark method is used to solve the equation. Taking the short span single supported beam bridges as object, the influence of approach fault on bridge vibration is analyzed. It is found that the settlement of abutment affects bridge vibration and with the settlement increases the impact of vehicle to bridge also increases explicitly. The dynamic amplification factor caused by the settlement is much bigger in short span than in long span. With the vehicle speed increases, the impact factor also increases and the influence region also expands. In addition, the settlement at the abutment causes the increase of vehicle accelerated velocity which is not affected by the span of bridge.