The reentry blackout phenomenon, which is the communication cut-off between the re-entry vehicle and ground station, is a crucial problem that needs to be addressed. To improve safety during reentry, a new mitigation method was proposed using the surface catalysis effect. However, this method has not been investigated extensively by experimental methods. In this study, we experimentally demonstrated the mitigation method using a 1 MW arc-heated wind tunnel and numerically clarified the mitigation mechanism. As a demonstration experiment, communication tests were conducted to compare the two cases. In the first case, a ceramic surface was used as a low catalytic wall, whereas in the second case, a copper surface was used as a high catalytic wall in the arc-heated wind tunnel. The experimental results indicated that the blackout occurred when alumina was used as the low catalytic wall. On the other hand, for the high catalytic wall using copper, blackout was avoided. The tests were reproduced in the wind tunnel using a numerical simulation technique. From the simulation results, the mitigation mechanism suggested that: (a) the number of nitrogen and oxygen atoms decreased due to catalysis; (b) forward reactions of electron impact ionization were suppressed due to the decrease in the number of atoms; and (c) the suppression of reactions decreased the number of electrons, thereby mitigating the reentry blackout. In addition, the numerical simulations performed on the reentry plasma around the re-entry capsule suggested that the mitigation mechanisms between the arc-heated wind flow and reentry plasma were similar despite the different airflow conditions.