NEPE propellants were prematurely aged at 65, 70, 75, and 80 degrees C, respectively. The strength limit of NEPE propellants was tested by the uniaxial tension test. Based on the aging mechanism of the micro-phase structure and the macro-mechanical properties of NEPE propellants, the aging process was divided into three stages: post curing stage, microstructure gradual degradation stage and accelerated chemical aging stage. Because nitrate ester is hardly to decompose at ambient temperatures, the post cure of NEPE propellants only occurs at higher temperatures. Thus, the life prediction of NEPE propellants should ignore the time of post cure. The service life of NEPE propellants at ambient temperatures should be determined by the second stage of high temperature accelerated aging. By analyzing the tensile strength of NEPE propellants aged at 65, 70, 75, and 80 degrees C, the service life prediction equation of NEPE propellants was established and the service life was predicted.