Based on an engineering example，the seismic response characteristic of high piled platform structure with eccentrically distributed plane stiffness of beam system is studied by response spectrum method and time history analysis.It shows that results of response spectrum method and artificial wave time history analysis are close under transverse earthquake action，while the result of natural wave is different due to wave selection.The calculation results of piles are close for 2D and 3D model，and the peak shear force of transverse beam model are close for 2D and 3D mode，while the peak bending moment of which differ greatly.The results of 3D response spectrum method and artificial wave time history analysis are close under longitudinal earthquake.The comparison of different calculation modes shows that the 3D response spectrum method has good adaptability.If the seismic precautionary intensity is greater than 7-degree，PHC pile is not suitable for this type of platform.Parametric analysis of the beam-plate connection rigidity coefficient λ shows that the effect of λ change on the internal forces of transverse or longitudinal beam is greater than that on the pile，the effect on the bending moment of transverse or longitudinal beam is greater than that on the shear force，and the influence degree under the longitudinal earthquake is greater than that under the transverse earthquake，which indicates that the constraint state between plate and beam changes the structural stiffness distribution，and then has regular influence on the seismic effect.