系统安全中存在含糊性和不可分辨性，Fuzzy综合评价只能从正面解决含糊性问题，而Vague集具有 对不确定数据更强、更灵活的直觉表达能力，由此提出把Vague集运用到综合评价当中，并使用改进层次分析法 确定各评价指标的权重，建立了基于Vague集的系统安全综合评价模型。通过对陕西某高层建筑火灾危险评价实 例证明，该模型能使系统安全评价结果更准确、合理。

There are two different sides of ambiguousness and in distinguishability among systematic safety.  Fuzzy synthetic assessment can only solve ambiguousness problem from front, but Vague sets have fairly strong and flexible intuition expression ability for handling indefinite data. From this, this paper suggests that Vague sets be used in the synthetic assessment, then determines the weight of each assessment index with improved AHP, and establishes the synthetic assessment model for systematic safety based on Vague sets. Through the assessment for a certain high building fire hazard in Shanxi Province, it proves that this model can make the assessment result of systematic safety more accurate and reasonable.