Abstract: The topology structure of the channel network in power line carrier communication is variable according to the different branches and loads. Each complex power line network can be decomposed into tree topology, mesh topology, ring topology, or any combination of these basic topology structures. Based on this, a bottom-up approach is adopted to model the tree topology, mesh topology, and ring topology of power lines using transmission line theory. The results show that changes in the topology of power line networks, such as changes in main line length, branch length, load impedance, etc., can have an impact on the channel transfer function.