Abstract: A fuzzy comprehensive evaluation method for evaluating the foundation stability of new buildings above work-out areas was proposed on the basis of the theory of fuzzy mathematics. A lot of factors that influence foundation stability were analyzed, and the evaluation elements were determined. A method for determining the subjection degree of primary factors was presented. The analytic hierarchy process was used to determine a judgment matrix, which distributes weight coefficients for every factor rationally. Based on the proposed method, a fuzzy comprehensive evaluation model was constructed, and the corresponding relation between the evaluation indexes and the level of foundation stability was obtained. The method was verified with three examples.