In order to realize the accurate control and simulation of communication environment for the multi-node network, a method for the frequency response calculating of multi-node power line channels based on the low-voltage power network topology. According to the power network topology, the shortest path search algorithm is used to obtain the trunk path. The parent-child relationship table produced by the algorithm based on breadth-first search is to gradually update the equivalent impedance of the node on the branch line from deep to shallow. And finally the transfer function is solved by the network parameter matrix concatenation. The clear and concise method is applicable to the low voltage distribution network or indoor power network of any given topology and adapted to the various time-varying load impedance model in the future. Simulation and experimental results show that this method can effectively simulate the channels between multiple nodes in a given power network topology.