<p>Driven by the growing demand for high-performance scintillators in high-temperature applications, such as industrial flaw detection and oil exploration, this work focuses on developing Tb³⁺-doped glass scintillators with anti-thermal-quenching properties. Capitalizing on the intrinsic advantages of glass matrices and the excellent thermal stability of the luminescence of Tb³⁺ ions, we designed a novel glass scintillator for high-temperature X-ray imaging. This was achieved by employing three synergistic strategies: (i) selecting an oxyfluoride glass host to provide a low-phonon-energy environment for the activators, (ii) increasing the structural densification of the glass network, and (iii) leveraging thermally enhanced energy transfer from Ce³⁺ to Tb³⁺. The resulting glass scintillators exhibit an exceptional optical transmittance (exceeding 88% at 542 nm), a record-breaking radioluminescence (RL) intensity (350% of a standard Bi₄Ge₃O₁₂ (BGO) crystal), and an outstanding imaging resolution of 24 lp mm⁻¹. Most notably, the material displays significant anti-thermal-quenching behavior, with its RL intensity at 633 K reaching 143% of its room-temperature (303 K) value. This performance far surpasses that of most reported and commercial scintillators, including BGO and CsI:Tl, whose RL intensities drop to approximately 1% under the same conditions. These results compellingly demonstrate the significant potential of the designed Tb³⁺-doped glass scintillators for high-temperature X-ray imaging and establish a promising strategic framework for the development of next-generation, thermally robust scintillating materials.</p>