Transmission line planning is affected by a variety of geographic information factors, and traditional path planning methods are difficult to meet the future intelligent planning needs. In this paper, based on the GIS platform for geographic information data processing, the triangular fuzzy number analytic hierarchy pro-cess (TFN-AHP) is utilized for weight analysis to construct the cost layer. Meanwhile, guided mechanism, dimension-reducing mechanism, and avoidance mechanism are proposed to improve the ant colony opti-mization (ACO) algorithm, to shorten the planning time and improve the route planning effect. Finally, a local area in Guizhou Province is selected for case study and compared with the results of traditional ACO, and the results prove the effectiveness of the transmission line planning model proposed in this paper.