Abstract: For the traditional network security situation assessment method,there is always a problem of large evaluation bias.In order to accurately analyze the network security situation,a network security situation assessment method of multi-stage large-scale network attack under the new network security was proposed.Firstly,based on the characteri-stics of multiple data sources under multi-stage large-scale network attack,the network security situation assessment model of multi-stage large-scale network attack was established based on information fusion.Next,large-scale network attack stage was identified,and the success probability of network attack and implementation probability of network attack phase were calculated.Finally,three indexes in CVSS was used for network security situation assessment.The exam-ple analysis shows that the proposed method is more suitable for practical application,and the evaluation results are accurate and effective.

Key words: Multi-stage large-scale network attack,Network security situation,Assessment method