Risk assessment is the core as well as the most difficult and time-consuming part in real estate project investment and decision-making. In this paper, on the basis of project investment risk assessment methods widely used at home and abroad currently, combined with modern fuzzy mathematical theory and methodology, a network model appropriate for the investment risk assessment of the overall process of real estate project is built, thereby quantifying the results of risk assessment, and applying the model to a certain real estate investment case. The results showed that, the risk assessment model can obtain relatively accurate results, which can be used in practical work.