Based on the research of business continuity and information security of the Internet of Things (IoT), a key business node identification model for the Internet of Things security is proposed. First, the business nodes are obtained based on the business process, and the importance decision matrix of business nodes is constructed by quantifying the evaluation attributes of nodes. Second, the attribute weights are improved by the analytic hierarchy process (AHP) and entropy weighting method from subjective and objective dimensions to form the combination weight decision matrix, and the analytic hierarchy process and entropy weighting VIKOR (AE-VIKOR) method are used to calculate the business node importance coefficient to identify the key nodes. Finally, according to the NSL-KDD dataset, the network security events of IoT network intrusion detection based on machine learning are monitored purposefully, and after the information security event occurs in the smart mobile phone, which impacts through IoT on the business system, the impact of the key business node on business continuity is analyzed, and the business continuity risk value is calculated to evaluate the business risk to prove the effectiveness of the model. The experimental results of the civil aviation departure business show that the AE-VIKOR method can effectively identify key business node, and the impact of the key business node on business continuity is analyzed, which further proves the efficiency and accuracy of the model in identifying the key business node.