In view of the complexity, uncertainty, and fuzziness of the factors involved in evaluating slope stability, based on the fuzzy matter-element theory, we calculated the objective and subjective weights of the influence factors using the analytic hierarchy process and the entropy weight method. Then, we established a fuzzy matter-element model based on the coefficients of combined weights that considers both objective and subjective factors. The problem of weight allocation can be avoided by employing our proposed method. A comprehensive evaluation can be made by using this matter-element model along with the subjective and objective weighting method, both of which make the best use of statistical information from samples, based on expert theories and experience, to obtain reasonable index weights. We conduct a case study to demonstrate that this method can not only accurately estimate the slope stability but also provides a new way to evaluate slope stability.