Abstract: Aiming at the location selection of new shunt cables in the process of urban network transformation, this paper first analyzes the preconditions of this problem, and provides a matrix idea for the engineering design scheme in the way of arrangement and combination; Secondly, based on the analysis of cable thermal resistance characteristics, the operating temperature of cable cluster is calculated by comprehensively considering the factors such as environment and load; Finally, the new cable location optimization model is established, and the data structure of the traditional particle swarm optimization algorithm is improved to adapt to the solution of large-scale problems. The calculation example adopts the new shunt cable under the 3×4 pipe laying mode, and the analysis verifies the rationality of the proposed optimization model and the effectiveness of the improved algorithm.