Commercial Bi4Ge3O12 (BGO) monocrystal scintillator is relatively complicated to produce and too expensive. Therefore, it is desired to look for alternative scintillating materials with simple process, low consumption, large size, and high efficiency. Here, glass‐ceramics (GC) with high volume fraction of crystal phase and high density by increasing the proportion of heavy metal fluorides in the composition were designed. And bulk Tb3+‐doped transparent BaGdF5 glass‐ceramics with 23.3% crystal volume ratio and density of 4.65 g/cm3 have been prepared. The structural, optical, and luminescent properties of precursor glass and GC were systematically explored through series of characterization techniques including X‐ray diffraction (XRD), transmittance spectra, transmission electron microscope (TEM), photoluminescence (PL) spectra, and X‐ray excited luminescence (XEL). After heat treatment, both PL emission and XEL intensity of GC are enhanced because of the movement of Tb3+ ions from the amorphous glass matrix into BaGdF5 nanocrystals, which possess lower phonon energy and better crystal field. The luminescent quantum efficiency of GC reaches 30.7% and the XEL intensity of GC is around 140% of that of the commercial BGO scintillating crystal. Our results demonstrate that BaGdF5:Tb3+ GC may act as efficient scintillator for X‐ray detection.