The current approaches to estimating the level of energy security are based on applying a comprehensive approach to selecting the factors that affect energy security and the dynamics of processes in this domain. This article reveals the application of the model of energy security estimation and strategizing based on the systemic description of energy security as an object of management: the integral system, elements and connections, functions, processes, and the system’s material. At the same time, this model is able to take into account the dynamics of technological, political, economic, and other factors operating in the country and on the global arena. The energy security estimation model developed uses a modern methodology of integrated estimation: a multiplicative form of the integrated index, a formalized definition of the safe existence limits in order to provide scientific substantiation of the threshold vector, a modified rationing method, the principal components method, and the sliding matrix method to substantiate dynamic weighting coefficients. The paper demonstrates the systemic approach application to shaping strategic goals in the energy security domain in the context of sustainable development; the trajectory of energy security development is calculated by the method of strategizing that applies the principle “future is determined by the trajectory to the future” instead of the classical forecasting “past determines the future”. In general, the article shows the possibility of unifying the process of formalizing energy security (according to the needs of the researcher: country, industry, energy network, supply chain) as an object of management, estimating energy security status, and strategizing the regulatory sphere transformation in accordance with the target values for monitoring the effectiveness of management.