随着互联网的普及,网络流量与日俱增。人们在享受着网络带来的便利的同时,也面临着各种各样的网络安全问题。因此,网络安全技术的发展受到人们的空前关注。入侵检测技术作为一种保障网络安全的有效手段,可以快速检测出网络攻击并立即预警。贝叶斯算法以其坚实的数学基础和强大的推理能力,被广泛应用在信息分类领域。本文提出一种改进的贝叶斯网络算法,利用互信息理论构造贝叶斯网络,并对未知攻击进行检测。 With the popularity of the Internet, network traffic is increasing. While enjoying the convenience brought by the network, people also face various network security problems. Therefore, the development of network security technology has received unprecedented attention. Intrusion detection technology as an effective means of ensuring network security, you can quickly detect a network attack and immediately alert. Bayesian algorithm is widely used in the field of information classification with its solid mathematical foundation and strong reasoning ability. In this paper, an improved Bayesian network algorithm is proposed, which constructs a Bayesian network using mutual information theory and detects unknown attacks.