Abstract In the design process of the transmission line of the traditional substation system, the plans and decisions often made by people, resulting in unsatisfactory line design results, which are not the most economical optimal results, and they are not even considered in the preliminary planning. Going to areas where lines cannot be erected has caused slow progress and poor accuracy in the feasibility study stage. This paper combines the ant colony intelligent algorithm with the geographic information system, and proposes a substation transmission line optimization model, which outputs the optimal path by inputting geographic information data. This model analyzes the entire process of the transmission line design stage and realizes the intelligent line selection. The analysis of the example in the article proves that the model has a better auxiliary function for the work of the substation line planning stage.