The rules of dimension change of plastic bonded explosive PBX-TATB charges during thermal cycling were studied in detail, and the methods of reducing the permanent expansion were studied. The results showed that the growth of PBX-TATB charges mainly occurred during the first several cycles, and after 20 cycles the dimension of the charges wouldn′t expand no longer. It also found that the growth of the pellet can be decreased remarkably by using a binder with high glass transition temperature (T_g) instead of fluoropolymer.