The study reports a significant enhancement in the X-ray excited persistent luminescence (XEPL) intensity of lanthanide-doped fluoride nanoparticles (NPs) by constructing dual heterogeneous interfaces in a double-shell nanostructure. This approach not only passivates surface quenchers, reducing non-radiative relaxation, but also reduces the formation energy of interfacial Frenkel defects, leading to increased trap concentration. The core@shell@shell structure was found to enhance the XEPL intensity by up to 40.9 times compared to conventional core NPs for various lanthanide activators (Dy, Pr, Er, Tm, Gd, Tb). The enhanced XEPL properties were confirmed through spectroscopic studies, including XEPL spectra, decay curves, and digital photographs. The improved XEPL performance was further validated through delayed XEPL-based 3D imaging, where the internal electrical structures of a watch were clearly visualized using a flexible film containing Y@Lu/Gd/Tb@Y NPs. This work highlights the potential of these enhanced XEPL NPs for low-dose and high-resolution 3D imaging in various scientific and practical applications.The study reports a significant enhancement in the X-ray excited persistent luminescence (XEPL) intensity of lanthanide-doped fluoride nanoparticles (NPs) by constructing dual heterogeneous interfaces in a double-shell nanostructure. This approach not only passivates surface quenchers, reducing non-radiative relaxation, but also reduces the formation energy of interfacial Frenkel defects, leading to increased trap concentration. The core@shell@shell structure was found to enhance the XEPL intensity by up to 40.9 times compared to conventional core NPs for various lanthanide activators (Dy, Pr, Er, Tm, Gd, Tb). The enhanced XEPL properties were confirmed through spectroscopic studies, including XEPL spectra, decay curves, and digital photographs. The improved XEPL performance was further validated through delayed XEPL-based 3D imaging, where the internal electrical structures of a watch were clearly visualized using a flexible film containing Y@Lu/Gd/Tb@Y NPs. This work highlights the potential of these enhanced XEPL NPs for low-dose and high-resolution 3D imaging in various scientific and practical applications.