Abstract: With the development of vehicle intelligent technology,the combination of network and vehicle becomes inevitable,which brings great convenience to people.At the same time,hackers can also use technical loopholes to attack vehicles,resulting in serious traffic accidents and even vehicle crashes.Based on this situation,vehicle information security technology has gradually become the focus of attention.In the face of endless network attacks on Internet of vehicles,situation awareness is needed to protect the Internet of vehicles.In order to improve the accuracy of IOV security situation awareness,this paper proposes a decision tree-based IOV security situation prediction model.Because network attacks often change abnormally by certain specific attri-butes,the process of attribute change is an attack method.The tree is classified according to these attributes,the information gain rate is used to build a decision tree,and the rules for decision are derived.Through experiments,the feasibility of the proposed algorithm in the security situation awareness of the Internet of Vehicles and the accuracy of the prediction results are verified.

Key words: Decision tree, Internet of vehicles security, Situation awareness