Abstract: Optimization of RCC dam construction schemes is a typical multi-attribute decision-making process that requires a comprehensive consideration of several factors such as construction period, utilization rate of machines, and investment scale. Most previous studies neglected the influence of differences in the experts’ knowledge and the fuzziness in the experts’ judgment on construction scheme decision and assumed the index weights subjectively in optimization of the schemes without a clear mathematical basis. This paper describes an optimization method of RCC dam construction schemes using an entropy-D model that, based on the D-number theory, does not need the completeness of decision-making information. First, the Pearson correlation test method is used to analyze the correlation between evaluation indexes obtained from simulations of four schemes. Then, index weights are determined using an entropy-weighted method and the D-number theory is applied to calculate the D-numbers of each scheme in different identification frames. Finally, combination rules of the D-numbers are determined and recursive combination is carried out according to the trust degrees of different experts and the weights of different indexes. And integration of these fusion results gives a comprehensive evaluation index of the schemes and hence an optimal scheme can be selected. Engineering applications show that this method can achieve an effective scheme optimization for RCC dam construction with incomplete decision information.