A novel Mg5SnB2O10: Eu3+, Bi3+ red phosphor is synthesized by a solid-state reaction, whose structure and photoluminescence properties are investigated through X-ray diffraction, diffuse reflection spectrum and photoluminescence spectrum. The excitation spectrum centred at 393 nm reveals the 7F0-5L6 characteristic transition of Eu3+, which matches well with the near ultraviolet chip for light emitting diode (LED). In the emission spectrum under 393 nm excitation, peaks at 591, 612 and 701 nm could be attributed to the transitions of 5D0-7F1, 5D0-7F2 and 5D0-7F4 of Eu3+, respectively. With the introduction of Bi, the emission intensity is improved due to the energy transfer from Bi3+ to Eu3+. In this paper, the optimal doping concentration of Eu3+ and Bi3+ is determined to study the photoluminescence properties and the optimal sample Mg4.89Eu0.1Bi0.01SnB2O10 is obtained. The integral intensity of the emission spectrum for Mg4.89Eu0.1Bi0.01SnB2O10 phosphor excited at 393 nm is about 1.1 times stronger than that of Y2O2S: Eu3+ excited at 394 nm.