An interval-valued intuitionistic fuzzy multiple attribute decision-making model is proposed based on the revised entropy and a new scoring function. In this model, the attribute values are the interval-valued intuitionistic fuzzy numbers, and the attribute weights are completely unknown. Firstly, a revised definition of the interval-valued intuitionistic fuzzy entropy is introduced, and the objective attribute weights are determined by using the entropy weight method. Then, according to the decision matrix and attribute weight, the synthesized attribute value of each project is got by using the interval-valued intuitionistic fuzzy weighted arithmetic average operator. The deficiencies of the current scoring functions which fail to sort or could not conform to the reality are analyzed, and a new scoring function is proposed. Finally, an example is given to illustrate the effectiveness of the proposed approach.