The object of this study is the influence of technological parameters on the extraction process from walnut shells. The main practical application of walnut is associated with the use of a kernel placed inside the shell. The kernel isolated after processing is used in confectionery, fat-and-oil, flour milling, pharmaceutical, and other industries. The walnut shell that remains after cleaning is waste and is usually disposed of. Analysis of studies reveals that walnut shells are rich in phenolic acids and related polyphenols, which are essentially a natural antibiotic with numerous healing effects. Along with this, crushed walnut shell is a universal organic, biodegradable, environmentally friendly, and valuable raw material with unique physical characteristics and chemical properties used in various sectors of the economy. Walnut shell is 52.3 % lignin, for comparison ‒ almond shell contains 28.9 %, pine nut – 40 % lignin. Studies show that lignin characterizes the level of strength of the shell, and in its chemical composition is a source of antioxidants. Various methods of extraction of biologically active substances from walnut shells are used. However, the results obtained by different methods have a wide range of data. Optimization of extraction processes has been carried out and its regularity was established. By the method of mathematical modeling, optimal extraction modes were revealed under which the most complete extraction of biologically active substances is observed. Optimal extraction modes have been developed.