Currently, the development of polymer composite materials based on ultrahigh molecular weight polyethylene (UHMWPE) is one of the urgent tasks of polymer materials science. This is primarily due to its special mechanical and tribological properties, owing to which UHMWPE is actively being implemented in various industries such as machine building, coating and medicine. However, in order to expand the scope of application, it is necessary to eliminate the disadvantages in the form of low surface hardness and strength. The most effective and economically feasible way to reduce disadvantages is to modify the polymer by introducing various types of fillers. In this paper, the effect of complex fillers including nano-CuO and 2-mercaptobenzthiazole on the physico-mechanical properties and structure of ultrahigh molecular weight polyethylene is analyzed. It is shown that the introduction of complex fillers into UHMWPE increases the deformation and strength properties, the compressive stress increased by 23…35% and the Shore D hardness by 5…6 % compared to the initial polymer. The developed composite materials were characterized using X-ray diffraction analysis, differential scanning calorimetry and scanning electron microscopy. A connection between the decrease in the degree of crystallinity of UHMWPE-based composites with an increase in the content of complex fillers was found. The formation of spherulites in the supramolecular structure of composites has been shown by electron microscopy. Based on the conducted research, it is concluded that the improvement of the physical and mechanical properties of composites is triggered by complex effect of fillers due to the improvement of their co. The developed polymer composite materials can be used as protective coatings and linings in engineering and technological equipment.