The development of white light emitting diodes (WLEDs) prepared with tricolor phosphors is limited by issues such as reabsorption, difficulty in controlling sample proportions, low thermal stability, etc. This study synthesized a series of single-host Ca2GdNbO6:xDy3+ (CGNO:xDy3+) phosphors using High-temperature Solid-state Reaction. Then the structure characteristics, luminescence, thermal stability, and morphology were analyzed in detail. The results showed that all the samples, emitted white light superposed by the blue at 483 nm and the yellow light at 575 nm under near-ultraviolet excitation, exhibit good quantum yield, excellent optical properties, and good moisture resistance. Besides, the CIE chromaticity coordinates (CIE) and luminous pictures of CGNO:xDy3+ phosphors both at 352 nm and 389 nm were investigated. Then, the properties of LED devices obtained by coating the aforementioned phosphors on 365 nm and 395 nm chips were characterized. The research confirmed that CGNO:xDy3+ are potential single-host white light phosphors in the field of lighting.