An energetic slurry formulation was designed by light-cured liquid resin， magnesium powder （Mg）， ammonium perchlorate， and burning rate regulator. The energetic grain was printed by Digital Light Processing（DLP） photocurable 3D printing technology. The combustion process， delay performance， uniformity， and compatibility of energetic grain were evaluated， and the influence factors of delay time were analyzed. The results show that the optimal mass fraction of energetic slurry formulation is 7.53% burning rate regulator， 62.37% ammonium perchlorate， 3.22% Mg， and 26.88% light-cured resin. Performance test of slurry displays that viscosity， curing time， curing hardness， and shrinkage are 325 mPa·s， 3.2 s， 2H， and 4.98%， respectively. A cylindrical energetic grain was successfully printed with the size of Φ6 mm×11.5 mm and the average density of 1.507 g·cm^-3. The printed energetic grain exhibits evenly distributed components， good compatibility， stable combustion process， bright yellow flame， and combustion residue rate of 4.98% without black smoke generation. The average delay time and burning rate are （12.43±0.0158） s and （0.805±0.0012） mm·s^-1， respectively. The obtained delay time meets the standard of long second delay composition， and the delay accuracy conforms the requirements of second delay composition. The influence on delay time gradually decreases from ammonium perchlorate， light-cured liquid resin， burning rate regulator to Mg. The delay time of energetic grain can be controlled to achieve diverse delay targets by adjusting component content of energetic slurry.