A series of Ca3Y(AlO)3(BO3)4:Eu3+,La3+ red phosphors have been successfully synthesized via a mixed-fuel microwave solution combustion synthesis. In this study, the structural, morphological and optical properties of the phosphors as a function of annealing temperature and time were systematically investigated. The X-ray diffraction analysis confirmed the formation of the hexagonal Ca3Y(AlO)3(BO3)4 structure at 900 °C and the powder crystallinity depends critically on the annealing condition. The diffuse reflectance and excitation spectra revealed that the phosphor exhibits a strong absorption in the near-ultraviolet region (396 nm) that matched well with NUV LEDs. Under 396 nm excitation, the Ca3Y(AlO)3(BO3)4:Eu3+ emits intense orange-red emissions, and the optimal fluorescence intensity was attained after annealing at 1000 °C for 5 h. Meanwhile, an appropriate amount of La3+ co-doping significantly enhanced the luminescence of Ca3Y(AlO)3(BO3)4:Eu3+, which were due to the environment distortion of the crystal field induced by the difference in ionic radius. The electroluminescence measurement confirmed that the Ca3Y(AlO)3(BO3)4:Eu3+,La3+ phosphor could be efficiently excited by commercial NUV LED chips. These results indicated that the synthesized Ca3Y(AlO)3(BO3)4:Eu3+,La3+ phosphor could serve as a potential red-emitting component for NUV based-white LEDs.