Based on grid of DEM,we take the lower reaches of Weihe flood data as a basis,and combined with Virtual GIS module of ERDAS 8.5,to realize visualized simulation in 3D of nonfountainhead flood according to principle of fountainhead and non2fountainhead.We demonstrate elementary dynamic submerge course of flooding,so as to impel the departments concerned to attached great importances to flood control,and to provide academic foundation for governmental planning measure,therefore to exploit wider prospect for developing governing flood work further.