关键词: 安全态势评估, 多源数据, 证据理论, 修正因子

Abstract: A security situation assessment model is proposed in this paper.One of the math function and the rectification function is used to design the experience function in the theory of evidence，the theory of evidence is brought into the security situation assessment.From correlating and fusing the data which is provided by the sensors deployed in the network to depict the curve of security situation，the whole process is completed.The security situation assessment model and the algorithm are verified.The results show that the problem of network security situation assessment is resolved very well by the use of the theory of evidence.At last the method how to apply this assessment model to large-scale network security situation assessment is introduced in this paper.

Key words: security situation assessment, multi-source data, theory of evidence, rectification factor