Abstract: Due to thermal stress, cracks will appear in plastic bonded explosive(PBX) in the experiment of thermal shock implemented by water-bathed method. With the application of acoustic emission testing device, thermal shock process was monitored by acoustic emission signal. The preliminary experiment showed that the acoustic signal brought in thermal shock not only reflected the different phase of cracks growth and located the damage, but also provided reliable experimental data and theoretical base for the study on mechanism and mode of PBX's thermal shock damage.