Abstract: This paper analyzed the characteristic of deep coal deposit synthetic exploration & the demand of the assistant decision support system of deep coal deposit synthetic exploration. On this basis, the system frame of the C/S and B/S mixed mode had been brought forward. According to the basic demand of the deep coal deposit information technology, the system was plotted out five primary function modules, which included data management, information query, 3D visualization display, data processing & assistant decision of synthetic exploration. The key technology presented which including GIS, database, data complex, data mining & knowledge expression. The above provided the whole method for the system development.