Abstract <p>In order to develop an effective method for investigating and predicting the deformation behavior of the electrical conductivity of conductive nanocomposite materials additionally reinforced with glass fibers, a numerical model was developed that takes into account the interrelationship of the properties of such composites at different scales of their structure. For the experimental verification of the developed multiscale model, composites based on polypropylene modified with multi-walled carbon nanotubes were fabricated. The resulting nanocomposites were additionally reinforced with layers of glass fabric, with the layers stacked in a 0°/90° pattern. This ensured the multiscale structure of the resulting composite material, as well as the isotropy of the electrical conductivity in the plane of the glass fabric in the composite. The uniaxial deformation of the fabricated glass fiber reinforced nanocomposites with simultaneous continuous measurement of their electrical resistance was carried out by experimental and numerical methods. The results of the numerical modeling were compared with the experimental data obtained for both the nanotube-filled polypropylene and the fabricated glass fiber-reinforced nanocomposites based on it. It was shown that the introduction of glass fiber into an electrically conductive nanocomposite increases the strain sensitivity of the electrical conductivity of the material under uniaxial deformation, which is adequately predicted by the proposed method of multiscale modeling, provided that the structural features of the composite are correctly reflected.</p>