The relevance of the research is explained by the existing contradiction of the subject area, which consists in the communication infrastructure of the critical information infrastructure (CII) object dynamically changing in the process of functioning, as well as the methods of the intruder's impact on the CII object, as well as the methods of the intruder's impact on the CII object, which create preconditions for reducing the level of information security and the capabilities of the existing methods of assessing the object's security based on signatures, expert approach, as well as methods and means of ensuring information security, which do not allow taking into account such dynamics of changes in the level of information security of the object. Purpose of the research. Provision of information security of communication infrastructure of CII objects by taking into account communication and configuration parameters, dynamics of interacting subjects.Research methods. Mathematical methods of systems theory and system analysis of probability theory, methods of graph theory, methods of simulation modeling.Results. The article presents a method of modeling of communication infrastructure that allows to form parametric accurate simulation models of the CII object to study the properties of security and stability, to simulate the impact of an intruder on the CII object. Novelty. A method of modeling the communication infrastructure based on configuration and communication parameters of the CII object has been developed, taking into account the dynamics of communication infrastructure interaction, its information security policy and intruder actions. Theoretical significance. Development of information security methods in the field of modeling the communication infrastructure of CII objects on the basis of hypergraphs, nested colored Petri nets, allowing to take into account the dynamics of interacting subjects (communication and configuration infrastructure, information security policy, the impact of the intruder).Practical significance. The modeling method allows to take into account configuration and communication peculiarities of construction and functioning of the CII object, parameters of the intruder's impact on the CII object, the existing security policy, to model the stability property, to conduct research of the influence of interacting subjects on the security of the CII object, to reduce the dependence on expert assessments, to receive parametrically justified assessments of the security of the communication infrastructure of the CII object.