Abstract: Path optimization of natural gas pipeline based on two-dimensional plane can hardly reflect the actual environment. In this paper, high-resolution discrete 3D terrain data was extracted using Global Mapper of GIS software and the Digital Elevation Model (DEM) was established. Based on the DEM, the path optimization model for the pipelines in hilly areas was established with the minimum length of natural gas pipeline as the evaluation index and the curvature radius of elastic installation as the constraint. Then the optimal surface path between two points was solved by the modified Dijkstra algorithm (A^* algorithm) in the mode of heuristic search. Finally, it was applied to simulate the actual landform. It is indicated that the DEM based on Global Mapper has the advantages of small workload and high precision and it can be used as the simulated landform effectively. Besides, the A^* algorithm is better in global convergence and calculation robustness and applicable to the solution of pipeline path optimization model. By virtue of A^* algorithm, the total pipeline length and the path fluctuation degree can be decreased effectively.