<p>Materials that can withstand high radiation doses are crucial for the development of various cutting-edge technologies, such as aerospace, next-generation fission, and future fusion energy. However, few materials can withstand intense radiation doses without suffering from irreversible materials degradation. Herein, we present a strategy to achieve high radiation tolerance by a dynamic in-situ defect recombination, where abundant solutes thermodynamically stabilized within the ceramic lattice combine with radiation-induced defects. We demonstrate that in high-entropy pyrochlore oxide (HEPO) based solid solutions, little microstructure damage is observed even after He²⁺ radiation with energy of 500 keV and 1 × 10¹⁷ ions/cm² fluence. HEPO solid solutions exhibit a counterintuitive reordering transition: their structural ordering improves rather than degrades after irradiation. This can be attributed to an in-situ defect recombination, which not only annihilates the radiation-induced defects but also alleviates the lattice distortions. This strategy represents a promising approach for developing materials with high radiation tolerance.</p>