At present, the multi-wave impedance model of the tower widely used in lightning protection analysis can not reflect the difference of the induced overvoltage of the transmission lines. Therefore, it is of great significance to carry out the transient modeling of lightning tower. This paper first deduces the fitting process of rational function, then selects the 8th order vector to fit the frequency response of the tower numerical model, and establishes the tower broadband equivalent circuit model based on the passive network synthesis theory and the pole-residue. Then based on CDEGS and ATP-EMTP joint simulation, the validity of the broadband modeling method is verified. Finally, the accuracy and engineering practice value of the broadband model are further verified by the scaled tower experiment.