In order to systematically compare the seismic performance of different station-bridge combination systems， two three-dimensional finite element nonlinear dynamic analysis models of station-bridge integrated structure and station-bridge separated structure are established based on a practical project. Based on the comprehensive consideration of the nonlinearity of the pier column and the nonlinear sliding friction effect between the spread footing foundation， the gravel cushion and the subway roof， the dynamic response of the two structural forms under strong earthquakes and the damage mechanism of the pier are discussed in depth. It shows that within the scope of this paper， the dynamic response of the subway station columns under the bridge piers in the two station bridge combination systems is greater than that of other columns. Compared with the station-bridge integrated structure， the station-bridge separation structure can effectively reduce the bending moment and shear response of the pier in the subway station column and bridge structure. The relative displacement of the pier and beam is smaller， but there is a certain residual displacement.At the same time， the damage level of piers in the station-bridge separation structure is lighter and the plastic state appears later than the ones in the station-bridge integrated structure. In conclusion， the seismic performance of the station-bridge separation structure is better， but in practical engineering， it is necessary to pay attention to the limitation of the residual displacement between the pier and girder， and the foundation slip.