A molecular design strategy based on a hybrid perovskite (TpyBiCl₅) is reported to overcome thermal quenching in X-ray scintillators through multi-excited state switching. The hybrid perovskite structure provides a platform to modulate luminescence centers, stabilizing triplet states and enhancing room-temperature phosphorescence quantum yield from 3.8% to 45% compared to its organic ligand (Tpy). The interactions between components enable mixing of different excited states, leading to switchable TADF and phosphorescence emissions with temperature changes. The TpyBiCl₅ scintillator exhibits detection limits of 38.92 nGy s⁻¹ at 213 K and 196.31 nGy s⁻¹ at 353 K, demonstrating its potential for addressing thermal quenching in scintillators. The material exhibits tri-mode emission (prompt fluorescence, TADF, and phosphorescence) due to electronic coupling between organic and inorganic components, with the rigid framework and enhanced spin-orbit coupling contributing to improved phosphorescence efficiency. The material shows excellent performance in temperature-dependent X-ray imaging, with color shifts in X-ray images from yellow to green as temperature increases, enabling high-resolution imaging at elevated temperatures. The study highlights the potential of hybrid perovskites for developing efficient scintillators that can operate in abnormal environments.A molecular design strategy based on a hybrid perovskite (TpyBiCl₅) is reported to overcome thermal quenching in X-ray scintillators through multi-excited state switching. The hybrid perovskite structure provides a platform to modulate luminescence centers, stabilizing triplet states and enhancing room-temperature phosphorescence quantum yield from 3.8% to 45% compared to its organic ligand (Tpy). The interactions between components enable mixing of different excited states, leading to switchable TADF and phosphorescence emissions with temperature changes. The TpyBiCl₅ scintillator exhibits detection limits of 38.92 nGy s⁻¹ at 213 K and 196.31 nGy s⁻¹ at 353 K, demonstrating its potential for addressing thermal quenching in scintillators. The material exhibits tri-mode emission (prompt fluorescence, TADF, and phosphorescence) due to electronic coupling between organic and inorganic components, with the rigid framework and enhanced spin-orbit coupling contributing to improved phosphorescence efficiency. The material shows excellent performance in temperature-dependent X-ray imaging, with color shifts in X-ray images from yellow to green as temperature increases, enabling high-resolution imaging at elevated temperatures. The study highlights the potential of hybrid perovskites for developing efficient scintillators that can operate in abnormal environments.