This paper presents a systematic investigation to develop a novel kind of luminescent low-temperature co-fired ceramics (LTCC) for white LED package. The material used was the CaO–B2O3–SiO2 glass-ceramics doped with Dy3+ prepared by a sol–gel process. The characterization for its sintered bodies was associated with photoluminescence, XRD, SEM, and microwave dielectric measurement method. The results reveal that the optimal luminescent properties of sintering bodies and the microstructure with Ca2SiO4 and SiO2 can be obtained at the sintering temperature of 875 °C. Our results indicated that under 352 nm UV light exciting, the emission spectra of the glass-ceramics consist of two emission bands: the blue band (487 nm) and yellow band (573 nm), with chromaticity coordinates right in white-light region. The obtained products show the dielectric constant approximate 5.70, dielectric loss about 0.012 at 1 MHz. This provides great potentials for the application in microelectronic LED packaging.