On the basis of the unified energy path model of the integrated energy network analysis, by assuming that the energy network is a lossless transmission network, a Bergeron equivalent calculation model of the integrated energy network time domain analysis is established, and calculation formulas of the wave velocity and wave impedance of the lossless integrated energy network are derived. The calculation process of the transient response of the integrated energy network is further given based on the nodal analysis method, which provides a new idea for the time domain analysis of complex networks.