如何确定Mass函数是D-S证据理论的棘手问题,本文从信息论的观点出发,提出一种新的计算Mass函数的算法。该算法依据证据体可信度因素和证据体与目标关联的相对熵来分配证据体的Mass函数,较全面反映证据体的不确定性。将方法应用于液压泵诊断中,结果表明它获取的Mass函数是符合实际情况的,具有较好的实用性,而且其算法容易实现。 How to determine the Mass function is a thorny issue of D-S evidence theory. This paper proposes a new algorithm to calculate the Mass function from the point of view of information theory. The algorithm allocates the Mass function of the body of evidence according to the credibility of the body of evidence and the relative entropy of the body of the evidence to the target, which fully reflects the uncertainty of the body of evidence. The method is applied to the diagnosis of hydraulic pump. The result shows that the Mass function it acquired is in line with the actual situation, has good practicability, and its algorithm is easy to implement.