Novel persistent luminescence (PersL) phosphors are emerging as potential candidates for up-to-data information storage devices owing to its large memory capacity, low cost, and rewritable capability. In this study, a novel photostimulated luminescence (PSL) phosphor was successfully developed through co-doping Eu2+ and La3+ ions in Ba4Si6O16 (BSO) host. Firstly, the crystal structure, photoluminescence (PL), and PL excitation (PLE) of BSO:xEu2+ were studied systematically. Under the UV light source irradiation, the as-prepared BSO:0.02Eu2+ sample exhibits the best PersL decay property. Secondly, by applying the strategy of trap depth engineering, outstanding PersL performance is observed when La3+ ions were introduced into BSO:0.02Eu2+ as well. Moreover, the trap distribution and dynamics of electron motion in BSO: Eu2+, La3+ are characterized using methods of thermoluminescence spectra. Finally, verified by 980/808 nm photostimulation, BSO: Eu2+, La3+ shows promising application in optical information systems with a good optical storage capacity. In addition, based on the analysis of experiment and theoretical calculation results, a tentative energy level schematic is proposed to illustrate the mechanism of PersL and PSL in BSO:0.02Eu2+, La3+.