The sustainable development of energy, economy and environment (3E for short) is a hot topic in the present world, people pay more and more attention to the research on this topic. There are many achievements about 3E made by our researchers; however, because of geographical differences or the specification of study object, most of these studies can not play realistic roles either in promoting otherpsilas study or in decision-making for policy maker. So we want to build a platform which contains all existed research results, and people can do scientific experiments and virtual simulations about the sustainable development of 3E on it. This platform is a Web-based decision support system which consists of resource warehouse (3E data warehouse, policy warehouse, and software warehouse), model warehouse and applications related with 3E development. With this platform, researchers can share resources with others for free and verify their idea or model by experiment; decision-makers can predict the future development trend of 3E using the model warehouse and help to work out measures. This paper mainly introduces how to build a Web-based DSS (Decision Support System) for the prediction and warning for sustainable development of 3E.