Under the earthquake, pounding between the beam and the bridge abutment causes great damages to skew girder bridge, and current study on pounding response is still less as the collision effect is complex. In order to study the displacement and collision force under Elcentro and Tianjin ground motion, a three-dimensional finite element computational model for seismic pounding of a 16m simply supported skew girder bridge was established and nonlinear time-history analysis was carried out with pounding element designed to simulate the pounding effect between beam and abutment. The results show that the displacement of side beam is more than that of middle beam in simply supported skew girder bridge. The maximum collision force of the side beam is more than that of middle beam, and the beam pounds the abutment several times. Appropriate expansion joint width should be set according to the displacement of the side beam when the expansion joint designed.