The characteristics of product decision-making of real estate projects are determined by the particularity of real estate projects. Because the development and construction period of real estate projects is long, the investment is large, many parties participate, there are many risk factors in the development process, and after the development is completed, it is unrepeatable, and most of them aim at profit. Real estate regulation and control is a long-term work, and it is urgent to establish a set of operational analysis and decision support platform that runs through the whole chain of real estate and connects national and local levels, so as to realize real-time data aggregation, online calculation of indicators, rapid organization of content, rapid assembly of functions and flexible customization of services. In this paper, BD (Big Data) technology is used to collect real estate-related market data such as land, housing and finance, macro-statistical data such as population, society and economy, as well as real estate policy and public opinion information, to carry out system design and technology development, and to establish a real estate DSS(Decision Supporting System) based on BD. The system is helpful to carry out dynamic monitoring, analysis and evaluation of the real estate market, and effectively supports the product decision-making of real estate projects.