The automatic mapping algorithm for the transmission line network wiring diagram is a very complex global optimization problem. It involves two aspects: the automatic layout of the plant site and the automatic planning of the transmission line. In this study, a specific idea and algorithm for solving this problem are given. The issue is divided into three parts: the first part uses the force-oriented algorithm to make the initial layout of the plant station position, and uses the simulated annealing algorithm to perform iterative calculation, which is realized by concurrent technology. The gravitational and repulsion coefficients are selected to obtain the initial layout of the initial plant with the least cost. In the second part, the A* algorithm is used to plan the transmission line, and a cost model of the line direction is constructed. The cost model is used to standardize the line and obtain a beautiful line layout. In the third part, the layout results are evaluated and feedbacked, and the common layout defects are eliminated through the program, which reduces manual intervention. At the same time, the study also processed the historical line and the newly added line, so that the algorithm can realize the layout planning of the newly added station line without changing the layout of the historical plant station. The experimental results show that the graphical results obtained by the method satisfy the advantages of beautiful line planning, reasonable layout, less crossover, and less corners.