Building a refined 3D geological model of coal mines and major hazard pre-warning based on the geological models are new challenges and new topics of the coal mine safety. This paper established a 3D geological model of the Wangjialing coal mine. This paper introduced the work flow of 3D Geological Modeling in the Wangjialing Coal Mine. 175 drill holes, 22 faults, 11 stratigraphic layers, 11 subsidence pillars, 10 goafs and water goafs, 6 abnormal areas, and 7 abandoned shafts were input into GIS system and the 3D model was established. Based on that, a series of professional applications, such as hazard warning of drifting face, design of work face, and calculation of reserves were realized.