Based on the combined use of the laser Doppler vibrometry method and finite element computer modeling, an approach is developed for studying the propagation of an elastic wave in carbon fiber composites. Computer modeling makes it possible to describe the multilevel structure of the material under investigation, taking into account the presence of structural defects (absence and rupture of bundles, loss of adhesion and void, etc.), as well as the stacking and mutual orientation of the layers. The calculated data on the propagation of an elastic wave in the volume of the sample obtained on the basis of modeling are supplemented by experimental data obtained on its surface using laser Doppler vibrometry. The total wave pattern makes it possible to reveal the change of the features of an elastic wave as it passes through defective regions of the composite. Based on the approach, a modal analysis of composites with a structure of arbitrary complexity can be carried out.