The changes in appearance, structure integrality, mass /volume change rate, mechanical sensitivity, mechanical performance and launch safety of casted RDX-based polymer bonded explosive(PBX) with time during aging were studied by an accelerated aging test with temperature cycle from -55 ℃ to 71 ℃. The aging test at 65, 75, 85, 95 ℃, and SEM and DMA study of aging samples were carried out. Results show that after 25 temperature cycles aging test, there is no visible fissure and pores in PBX, and the structural integrity does not change, and the mass/volume change rate is less than 1%. The impact sensitivity increases to 16%. The explosion does not occur under the impact conditions of drop weight of 400 kg and drop height of 3 m. The compressive strength increases, and the compression ratio decreases, and the mechanical properties of the PBX deteriorate obviously. The compressive strength increases by 47.5% and compression ratio decreases by 9.8% after aging 252 d at 65 ℃. With the aging time extended, the dynamic mechanical loss peak(tanδ) of β relaxation decreases, the crossing degree of polymer network increases and polymer combine with filling material tightly, showing that crossing reaction of post curing is one of the reason about mechanical properties deterioration.