China's plateau regions are vast, with low transportation efficiency and high risks associated with vehicle transport. In recent years, scholars have proposed the concept of drone-based freight transport, where route planning has become an important research direction. The A* algorithm is a heuristic algorithm used for path planning. This paper analyzes the theoretical aspects of the A* algorithm and integrates constraints related to drone flight performance to derive design theory basis for route planning parameters. Additionally, it proposes a stable and effective weighting function. Using MATLAB, we constructed a digital elevation map (DEM) of a specific plateau region, set different obstacle conditions, and successfully planned the shortest route that meets design requirements. The results demonstrate that this method can meet the needs of route planning in complex terrains of plateau regions.