In allusion to the problem of difficulty in analyzing initial travelling wave transmission path due to complex topolo- gy structure of the power grid below 500 kV voltage class, this paper presents a kind of optimized configuration method for travelling wave locating device based on network decomposition. This method firstly decomposes original networks into sim- ple tree networks and ring networks from root nodes and respectively solves the shortest distance matrix of each network. Then, by using the shortest path algorithm, it can solve the shortest distance between any two substations in th...