A series of Sr2GdNbO6:xEu3+ (x=0.04-0.12) red phosphors were prepared by a high-temperature solid-phase method, and the target products were characterized by X-ray diffraction, UV-Vis spectrophotometry and fluorescence spectroscopy. The results show that the synthesized phosphor has a monoclinic crystal structure with the space group P21/c. The structural analysis indicates that doped europium replaces Gd3+ ion in the matrix Sr2GdNbO6 with the chemical state of Eu3+ ion, thus forming a single crystal structure phosphor. Sr2GdNbO6:Eu3+ phosphor exhibits a red-orange emission under dual-wavelength excitation of blue light λex of 468 nm and near-ultraviolet light λex of 395 nm, and the main emission peaks are centered at wavelengths of 622 nm and 593 nm, which belong to the 5D0→7F2 and 5D0→7F1 energy level transitions of Eu3+, respectively. When the doping amount (x) of Eu3+ is 8%, its luminescence quantum efficiency for blue light excitation reaches the maximum value of 16%. Based on the analysis and comparison of the temperature (295-568 K) effect on the emission intensity and quantum efficiency under dual-wavelength excitation, the phosphor has a high luminescence quantum efficiency under the excitation of blue light λex of 468 nm and a higher thermal stability. Under the excitation of blue light, the average fluorescence decay lifetime of the sample Sr2GdNbO6: 0.08Eu3+ is 0.841 ms, the color coordinates are (0.648, 0.368), and the luminescence purity reaches 93%. This phosphor is a kind of red fluorescent material with the dual-wavelength response for a promising potential application.