The use of high-temperature inert heat carriers, in particular superheated steam, has become widespread in the technology of frying food products. This process is because superheated steam has significant advantages over other heat carriers used in thermal treatment. Insufficient study of the process of frying barley grain with overloaded steam, unjustified fear for preservation of the quality of the finished product prevent the development of a general method of calculating the process of frying, makes it challenging to choose optimal processing modes and prevents the introduction of frying techniques and technologies into the feed industry. In this connection, it is very relevant to study the mechanism of heat and mass when frying barley grain with overheated steam using mathematical modelling methods. The spatial coordinates and time were taken as the independent coordinates of any point of the wet body. The model of the process of heat and mass transfer in frying barley grain presented by the system of differential equations of the second order in partial derivatives has been developed and solved by numerical methods. Good convergence of calculated and experimental data confirmed the expediency of using a mathematical model for process calculation and analysis of physical and chemical phenomena, development of high-efficiency roasting machines and program-logic algorithms for controlling technological parameters.