According to the characteristics of combat simulation model data, this paper proposes a credibility evaluation method of source data based on Jousselme evidence distance. According to the simulation model, a combat evaluation index system is constructed, the type of output simulation data is determined, the simulation data is quantified as evidence source data by using an expert evaluation method, the objective weight of the evidence source data is calculated according to the Jousselme evidence distance and the eigenvector method, and the expert weight is evaluated by using the eigenvector method as a subjective weight. According to the two kinds of weights, the comprehensive weight is obtained, and the original evidence source data is modified by using the comprehensive weight, and the credibility vector of the simulation data is obtained through multiple evidence fusion. Through the example of simulation data credibility evaluation, the results show that the method is feasible and accurate.