The problem of prevention of deviant behavior of minors is particularly relevant at present due to the relation of this age group to the most socially vulnerable category, as well as the growth of socially dangerous offenses and crimes committed by minors. The purpose of this study is to analyze, diagnose and identify the states and properties of adolescents’ personalities based on the Freiburg Personality Inventory (FPI), which are a manifestation of predisposition to deviant behavior. Within the framework of this study, we examined 12 input factors identified by I. Farenberg, H. Zarg, R. G. Gampel, taking into account the modification and adaptation by A. A. Krylov and T. I. Ronginskaya in collaboration with F. Korodi. We have defined the following tasks: the subject area has been studied, membership functions have been selected by applying the expert assessment method for input and output variables, intermediate membership functions have been determined by the pairwise comparison method, fuzzy rules that satisfy the completeness and consistency condition have been defined and supplemented, the hierarchical structure of the system has been formed, and other methods have been applied that allow increasing the system’s performance, the system has been tested on real data. The fuzzy production model proposed on the basis of the Freiburg Personality Inventory (FPI) can be used for the purposes of preventing deviant behavior in minors and allows diagnosing and analyzing the state and personality traits of adolescents in order to prevent them from committing offenses and crimes.