The blue phosphors designed as BaAl2Si2O8∶Tb3+, Ce3+ were prepared with high temperature solid-state reaction. The luminescence properties and mechanism of Tb3+, Ce3+, Tb3+ and Ce3+ Co-doped samples were discussed. Energy transfer between Ce3+ and Tb3+ in the sample was analyzed. The samples were tested with XRD, fluorescence spectra, color coordinates and so on. The results have shown that a small number of Tb3+, Ce3+ ions doping fail to change the crystal structure of BaAl2Si2O8. BaAl2Si2O8∶Tb3+ shows bright green. Emission spectra are the narrow-band spectral lines composed by peak-to-peak value of 487, 545, 583 and 621 nm, which are the typical emission peak generated due to 5D4→7FJ(J=6, 5, 4, 3) transition of Tb3+ ions. The incorporation of Ce3+ not only makes the excitation spectra of BaAl2Si2O8∶Tb3+ from the narrow band excitation to broadband excitation increases the spectral band diversity. The luminous intensity has obvious enhancement, and the color also has some coordination, which makes it more flexible in practical application. The reason for the enhancement of luminescence intensity is not only because of the sensitization of Ce3+ ions, but also due to the energy transfer between Tb3+ and Ce3+. The critical distance of energy transfer has been calculated with the concentration quenching method, which is 153.45 nm. The energy transfer mechanism is ascribed to the dipole-dipole interaction. When the Tb3+ion concentration was increased to 0.07 the transfer efficiency increased to 76.04%.