Abstract: In complex geographical environment, the irregular terrain influences wave propagation, and different media make different influences on the wave propagation. In order to make the prediction of wave propagation characteristics more accurate and more effective, this paper uses the image segmentation algorithm to realize the classification of the surface media, sets different electromagnetic parameters for different medium and combines with the Digital Elevation Model(DEM) data to build the geographical model that has the terrain fluctuation information and the surface electromagnetic parameters. On this basis, this paper does the grid subdivision to the surface electromagnetic information and uses the parabolic equation(PE) model to predict the wave propagation characteristics in the complex geographical environment.