In this work, the authors have considered the effect of short-term nonthermal action of microwave radiation on the distribution of radiative recombination centers in SiC/por-SiC/Dy2O3 structures. The analysis of photoluminescence spectra of these structures excited by the radiation with an energy lower than the band gap in the 4H-SiC crystalline substrate has shown that the short-term action of microwave radiation leads to the migration of dislocations and, as a consequence, to redistribution of radiative recombination centers and local symmetry change.