A short-time X-ray-induced long afterglow luminescent material, Ca₃(BO₃)₂:Pr³⁺, has been developed. The results showed that the phosphor exhibited excellent multiband long afterglow luminescence under X-ray excitation, with the afterglow emission peak primarily located at ultraviolet (270 and 302 nm), green (540 nm), and red (610 nm), corresponding to the 4f5d→³H_{4, 5}, ³P₀→³H₄,³P₀→³H₆ transitions of Pr³⁺, respectively. More importantly, when X-ray irradiation was applied for 30 s, the intensity of the afterglow after 3 h decayremained 3.9 times that of the background. Even with only 5 s of X-ray irradiation, it can also produce a long afterglow persisting for more than 3 h. In addition, Ca₃(BO₃)₂:Pr³⁺ exhibited excellent photostimulated performance, producing stable and intense light under periodic irradiation with a 980 nm laser. The thermoluminescence spectra results showed that there were traps with adepth of 0.8 eV, which resulted in excellent long afterglow and photostimulated properties. These results indicated that Ca₃(BO₃)₂:Pr³⁺ was an excellent X-ray-induced long afterglow luminescent material, which was expected to be used as an in vivo light source for human photodynamic therapy.