Tb3+-doped germanate glass ceramics containing CaF2 nanocrystals were prepared by melt quenching method with subsequent heat treatment. Their microstructures were investigated by XRD and TEM techniques. Their optical properties were studied by the transmittance, the photoluminescence, and the X-ray excited luminescence (XEL). The luminescence intensity in the glass ceramics under 377 nm light and X-ray excitations is significantly enhanced. The maximum integrated XEL intensity of the glass ceramics is about 50% of that of the commercial Bi4Ge3O12 (BGO) scintillating crystal. The results indicate that Tb3+-doped germanate glass ceramic could be a promising scintillating material used in X-ray detection for slow event.