Discrete information widely exists in many areas such as expert systems, pattern classification, and decision analysis. To solve the problem on the kind of information fusion, a method for the combining evidence of discrete intervalvalued belief structures is proposed. Firstly, each discrete evidence is separated into a kind of single-valued evidences. Then, the bodies of intra-group evidences are modified with the objective of minimizing evidence conflict and combined by using the evidential reasoning(ER) approach. Finally, the bodies of extra-group evidences are modified and combined by using the same method. It not only solves the internal and external conflict problems of the discrete interval evidence, but also greatly reduces the computational complexity. The numerical examples show the efficiency and rationality of the proposed approach.