In this paper, the luminescence properties of the long persistent phosphor (LPP) were apparently improved by combining with photonic crystal (PC). An optimized PC can double the afterglow intensity and prolong 1.7 times of the afterglow time of SrAl2O4: Eu, a commercially available LPP, without any dopants. These results were ascribed to the stopband effect of the PC. The PC combined LPP structure was beneficial for the applications of LPP in emergency indication which called for brighter afterglow intensity and longer afterglow time.