This paper mainly analyzes methods and technology of three-dimensional terrain with terrain module in MultiGen Creator2.6.According to character of real-time,accuracy and reality in terrain modeling,it gives the application scheme based on the terrain of space launch site.An new source data of terrain(grid map) conversion method is proposed.The authors sum up paste texture with contour strip and also put forward an method of combining Polymesh/Irregular Mesh algorithm with sampling mesh predigestion algorithm.Projection method and ellipsoid,setting LOD are chosen,an effective 3D terrain application project is given.This paper generates a three-dimensional terrain of space launch site with perfect visual effect,and the terrain has been applied to the three-dimensional simulation system.