Abstract: The digital geological survey system is software penetrating the whole process of geological and mineral resource survey. It covers digital mapping, geological and mineral resource survey, mineral resource exploration, orebody computer simulation, ore grade estimates, estimates of resources, optimization of the mine mining system etc. Proceeding from the applied technology, the key technology and its application in the digital geological survey system are discussed in aspects of the data “layer” model, data stream “pool” technology, inherited technology of data models of different stages and interoperable technology of data. Through data gathering, management and integrated processing and result expression based on the seamless integrative technology, the digitalization of the whole geological survey process is displayed with respect to the mineral deposit modeling technology of the entity or ore block, grade estimates and reserve estimates, which has not only lowered the threshold of the application of high-technology for geological workers, but also greatly improved the research precision and efficiency and enriched the expression and service forms of the outputs. The digital geological survey system will become the mainstream software system of China’s geological survey with improvement of the system and upgrading of its application.