The paper introduced overall architecture, data sources and processing, key indices information and system functions of decision support information system of coal enterprise in details by an example of decision support information system of Longkou Mining Group Co., Ltd.. The system uses technologies such as DTS and middleware to access data, uses subject-oriented multidimensional table structure of data warehouse and ODS layer table structure corresponding to business system to store data, establishes an architecture of key corporate indices which contains 45 key indices through analysis of types and attributes of various data, and adopts mathematical models such as year-on-year analysis, chain analysis and trend analysis for data analysis and presentation, so as to achieve decision support.