Introduction. Currently, the development of science and technology requires the creation of new polymer composites with high technical characteristics for various industries. One of the primary methods to improve the physical and technical characteristics of polymer composites based on thermoplastic elastomers is by incorporation of natural fillers. In the Kyrgyz Republic, there is particular interest in using fine mineral fillers extracted from local natural resources. The minerals and rocks found in the region are charac terized by high availability, extensive reserves, and a variety of properties. The accumulated experience in research and practical application opens up prospects for using these materials to create polymer composites with unique characteristics. This opens up new possibilities for using the cavitation process in various industrial applications, including the grinding of materials. Methods and materials. An experimental hydrocavitation mill has been developed to produce fine powders from minerals and rocks intended for use as fillers in polymer composites. The physicochemical properties of polymer composites and their raw materials were studied using modern instruments and equipment. The fractional composition and physical and technical characteristics of some minerals and rocks used to obtain active fillers for polymer composites are given. Results and Discussion. The fractional composition of crushed fillers with a particle size of less than 0.31 mm is distributed as follows: finely ground basalt – 7.3%, wollastonite – 44.6%, marble dust – 50.26%, brown coal powder – 47.56%. The analysis shows that among the studied fillers, finely ground basalt contains the smallest amount of fine fractions, which is due to its high hardness compared to other minerals such as wollastonite, marble, and coal. Physical and mechanical studies of the resulting polymer composites showed that when finely ground basalt is added, an uneven distribution of basalt powder in the polymer matrix is observed, which leads to a decrease in the strength characteristics of the composite. Therefore, to obtain a more durable material, it is necessary to grind minerals and rocks to the level of microparticles using the cavitation effect. For this purpose, a laboratory mill was created that operates based on the cavitation effect. Fillers at the level of micro- and nanoparticles were obtained using the developed hydro cavitation mill. The physical and technical characteristics of polymer composites with additives of the resulting nanofillers have been determined. The compressive strength of composites with mineral fillers (fraction less than 0.31 mm, content of wollastonite filler in the composite – 25.2%) was 5.47 MPa, with basalt f iller – 5.2 MPa, and with leather powder (dust) – 4.25 MPa. Fillers at the level of micro- and nanoparticles were obtained using the developed hydro cavitation mill. The physical and technical characteristics of polymer composites with additives of the resulting nanofillers have been determined. The compressive strength of composites with mineral fillers (fraction less than 0.31 mm, content of wollastonite filler in the composite – 25.2%) was 5.47 MPa, with basalt filler – 5.2 MPa, and with leather powder (dust) – 4.25 MPa. The compressive strength of the composite with the addition of carbon filler (13.2%) was 4.2 MPa. The introduction of up to 14.2% of mineral fillers into the composition of the composite increases its heat resistance: when adding basalt filler – up to 106 °C, and wollastonite – up to 114 °C. Conclusion. The fractional composition of mineral fillers based on inorganic raw materials studied for their use in creating polymer composites. A hydro cavitation mill was made and a method for processing fillers from minerals and rocks was developed. New polymer composites were obtained with the addition of basalt, wollastonite, marble, and leather industry waste. Studies have been carried out on the physical and technical characteristics of these polymer composites depending on the content of fillers, such as basalt, wollastonite, marble and leather industry waste.