Abstract: In order to solve the problem that any non-sinusoidal signal cannot be used to calculate the rail impedance due to the multiple frequency components, making it difficult to realize time-domain analysis of the ZPW-2000A track circuit. This paper proposes a Simulink model of the ZPW-2000A track circuit based on the waveform relaxation method. The model enables time-domain analysis of the track circuit under non-sinusoidal excitation. Firstly, the rail lines in the track circuit are treated as multi-conductor transmission lines. Their transmission line equations are decoupled through linear transformation, and a waveform relaxation-based transmission line model of the track circuit is established by disjoint two-port networks, the characteristic impedance and transfer function for arbitrary signal frequencies are replaced by lumped-parameter networks, combination with the waveform relaxation method, the track circuit is analyzed in time-domain. Secondly, considering with compensation capacitors and tuning units, a time-domain analysis simulation model of the ZPW-2000A track circuit is built in Simulink. The proposed method and the finite-difference time-domain method are compared with experimental data, which show that the relative error of the proposed method is only 6.58%, lower than that of the finite-difference time-domain method. This study provides a new theoretical model for time-domain response analysis and anti-interference analysis of track circuits under arbitrary non-periodic signal excitation.