For the irregular rotational displacement of curved girder bridge under seismic action there are some limits to calculate collision effect with pounding element approach. In order to analyze the inhomogeneous distributing rule of seismic collision effect for curved girder bridge, the new approach of explicit dynamic contact algorithm is presented. Seismic impactive response characteristic of girder, pier and block is analyzed. The results indicated that pounding action between girder and abutment limits longitudinal displacement of girder and makes bending moment of fixed pier less than that with collision effect unconsidered. After pounding the radial stress of block inside and outside the curve distribute severely inhomogeneously. The radial stress of block outside the curve is more than that inside the curve distinctly. This can provide theoretical guide for interpretation of the seismic damage of pounding for curved girder bridge.