Phosphors SrAl2O4 doped by Eu2+ and Dy3+ ions were synthesized by a solid-state reaction at 1300 ℃ under mild reducing atmosphere of N2 -H2 . The properties of afterglow and thermoluminescence spectra of SrAl2O4:Eu2+and SrAl2O4:Eu2+, Dy3+ were compared and the influence on trap levels of SrAl2O4:Eu2+by codoping Dy3+ was also studied. From the XRD and photoluminescence results, the crystal phase and luminescence band are not changed by codoping Dy3+. The thermoluminescence spectra show that the dopant of Eu2+ions could lead into two trap levels with different depth in SrAl2O4. The result of comparison of thermoluminescence properties of SrAl2O4:Eu2+and SrAl2O4:Eu2+, Dy3+ after different delay time indicates that the density of the original shallow traps is increased by the codopant of Dy3+, and the luminescence performance is improved. The thermoluminescence with different delay time indicates that the luminescence decay difference and electron transfer between trap levels in SrAl2O4:Eu2+, Dy3+ may result in the complicated decay phenomena of the afterglow.