The article is devoted to the development of a method of ultra-jet diagnostics of damage to carbon fiber panels, based on the high-speed impact of a liquid jet on the surface of a sample, the results of which are judged on its quality indicators. It is shown that the informative criteria for assessing the quality of carbon fiber panels as a result of ultra-jet diagnostics are the amount of stratification of the composite material and the depth of the cavity. Based on the analysis of experimental data, it is proved that the method of ultra-jet diagnostics makes it possible to assess the level of defectiveness of a carbon fiber panel formed as a result of thermocyclic tests of samples of various durations. Dependences are constructed according to which it is possible to observe a change in the informative (geometric parameters) of samples depending on the formed damage as a result of previously conducted thermocyclic tests. The presented material is part of the ongoing comprehensive research on the assessment of the possibility of using the proposed method of ultra-jet diagnostics to assess the quality of composite materials used in rocket and space technology.