To evaluate the environmental adaptability of the pressed RDX-based aluminized explosive(JHL-X),the internal damage,safety and mechanical performance of grain before and after thermal shock of JHL-X were studied by -55-70 ℃ temperature cycle impact test. The safety performance of this explosive was characterized by spontaneous ignition temperature and shock wave sensitivity. The mechanical performance was characterized by elasticity modulus,compression strength and fracture strain. Results show that the main damage of the JHL-X explosive grain interior after the thermal shock is micro-pores and micro-cracks. Its safety property decreases slightly. The spontaneous ignition temperature drops from 211 ℃ to 208 ℃,and the shock wave sensitivity increases from 51.5 mm to 53.5 mm. The elasticity modulus and compression strength increase by 85.3% and 37.7%,respectively,while the fracture strain decreases 29.2%.