The temperature-dependent optical properties of lanthanide-doped phosphors have been enthusiastically investigated in the fields of biomedicine, night-vision security, and optical information storage. In this work, the dynamically varying temperature-dependent photoluminescence and long persistent luminescence at low temperature (4–250 K) in the CaSrNb₂O₇:Pr³⁺ phosphor are explored. The photoluminescence of CaSrNb₂O₇:Pr³⁺ is white and the matrix emits cyan at 470 nm under 325 nm excitation at 84 K, whereas the CaSrNb₂O₇:Pr³⁺ phosphor exhibits bright red long persistent luminescence for more than 400 s at 250 K. Moreover, the CaSrNb₂O₇:Pr³⁺ exhibits a dramatic photoluminescence transition from white to red as the temperature rises by thermal quenching and the trap compensation luminescence. This optical property at low temperature shows great superiority not only in biomedicine and cryotherapy as a means of visualizing safe and non-toxic detection but also opens up new opportunities in the field of space remote sensing superconductivity.