A mathematical model of obstacle limit surfaces for military airfield obstacle free space is established through airfield obstacle free space analysis.Based on the model,triangle mesh elevation model of military airfield obstacle free space is built by using the software-ArcGIS,and the 3-D display result is obtained.It is convenient to evaluate military airfield obstacle for superimposing digital elevation model(DEM)with military airfield topographic map.Thus it improves the efficiency greatly.It lays the foundation for the application of geographic information systems(GIS)in the management of military airfield obstacle free space.