The finite element method has the disadvantage of being time-consuming and is not suitable for evaluating the seismic performance of structures that require multiple response analyses. A genera-lized single degree of freedom model for linear seismic response analysis of cantilever structures was stu-died, and the polynomial shaped functions and single degree of freedom models based on the polynomial shaped functions were proposed. The effectiveness of the single degree of freedom model based on the polynomial shaped functions for structural response analysis under typical seismic wave excitation was investigated through comparative analysis with the finite element analysis results. The results show that the average error of the proposed generalized single degree of freedom model based on polynomial functions is 7.20%. To improve the modeling accuracy, it is recommended to use the method of applying horizontal concentrated loads for polynomial function parameter estimation.