This paper, considering Demsper rule's disadvantage in aggregating the expertise of high conflict, presents the evidence conflict degree based on conflict coefficient and Jousselme distance. The objective expert weight is computed by using the evidence conflict degree. Then Demsper rule is used to aggregate the modified expertise. Finally, a new probability degree formula is established and the belief interval method based on probability degree is used for decision-making. The numerical examples illustrate that the proposed method is more efficient in combining the conflict expertise than several improved DS methods and compared with the maximum belief function method and plausibility function method, the belief interval method proposed is more scientific.