Abstract:Based on the analysis of factors affecting credibility of large complex simulation systems, a credibility index system was given. Because credibility evaluation of large complex simulation systems involves lots of qualitative indices with multiple levels and granularities, hierarchical linguistic variables were used to acquire their evaluation information, and the two-tuple linguistic method was used to deal with the evaluation information with multiple sources and granularities,and the credibility quantification of large complex simulation systems was implemented. Practical applications proved that this quantification method is effective.