Abstract: The shape of mineral resources buried underground is complex and highly varied and there are a great variety of data sources. The problem that needs to be urgently solved at present is to how to estimate the resources under the control of certain engineering work scientifically, rationally, accurately, flexibly and efficiently and complete various kinds of maps and tables for estimates of resources so as to meet the requirements of different work. The application of the technology of the digital geological survey system in estimates of resources is an effective way for solving the above-mentioned problem. The digital geological survey system is based on the GIS technology, and under the support of the computer software and hardware and by integrating the computer graphics, computer artificial intelligence and database technique, the authors achieved the data expression in the full process of the collection, management, storage, storage, map-making, analysis and result output of multi-source and enormous data of geoscience data and the seamless connection in the full digitalization process from field work to compilation and submission of results. This application in the Qulong ore district fully embodies the ability of this system to treat multi-source and enormous geoscience data scientifically and with high efficiency.