Currently, the problem of power outages in the power supply systems of objects of the internal Affairs bodies remains relevant. The article analyzes the statistics of emergency shutdowns of electrical equipment caused by accidents or unplanned shutdowns of power grid facilities. The classification of categories of consumers whose interruption of power supply may entail a danger to people's lives, a threat to the security of the state, significant material damage, disruption of complex technological process, disruption of the functioning of particularly important elements of public utilities, communication and television facilities. For ensuring appropriate level of reliability of power supply of the most important consumers, the block diagram of uninterrupted power supply of technical means of objects of law-enforcement bodies, on the basis of the combined use of sources of uninterrupted power supply and the device of multistage automatic input of a reserve, allowing to provide the constant mode of power supply of the most responsible receivers of electric energy is developed. Modeling and calculation of the integrated indicator of the effectiveness of the system of uninterrupted power supply of technical means of the objects of the police Department. Assess the effectiveness of the systems of uninterruptible power supply ATS a structural-parametric model that allows to quantify the efficiency of the uninterrupted power supply of objects of the internal Affairs bodies. The General logic-probabilistic method and the technology of automated structural-logical modeling are used for the computational experiment.