The object of research is the microstructure of glass-basalt-plastic composite pipes and the relationship between their multifractal characteristics and tensile strength. The study focuses on exploring how structural parameters influence the mechanical properties of these composite materials. Method. Physical experiments were conducted to measure and analyze the tensile strength of glass-basalt-plastic composite pipes. The methodology included strength testing and multifractal analysis to assess the structural heterogeneity of the materials. Sensitivity coefficients were calculated to quantify the influence of Renyi spectrum fractal dimensions of the pipe matrix fibers on tensile strength. The fractal dimensions of the fiber matrix (e.g., ) were evaluated, and their ranges were ranked based on their correlation with strength indicators. Results. The microstructure of the composite pipes exhibits significant heterogeneity, complicating the development of predictive models for their quality based on structural parameters. Multifractal analysis revealed the distribution of fiber and epoxy matrix regions within the pipes. Sensitivity coefficients established relationships between tensile strength and fractal dimensions, with key ranges identified:  for  for  for  for and  for  Mathematical modeling provided predictive formulas for tensile strength with a correlation coefficient  for key fractal parameters. These models offer an express method for evaluating the tensile strength of glass-basalt-plastic composite pipes, enhancing quality control processes.