Three different models are discussed in this paper, which are consolidation single tower model with body flexibility considered, linear single tower model based on m analysis method and nonlinear single tower model based on p-y curve analysis method, respectively. Seismic responses of these models are analyzed under ground motion inputs of El-Centro Earthquake and Kobe Earthquake and the calculation results are compared in this paper. The result turns out that the simulation method of linear single tower model of open caisson based on m analysis method produces larger structual response than that of the nonlinear single tower model based on p-y curve analysis method. While the simulation method of linear single tower model of pile group foundation based on m analysis method matches very well with that of nonlinear single tower method based on py curve analysis method.