Abstract: The GAP/PEG/TMP/IPDI energetic binder film was synthesized by using PEG and GAP as raw materials, trimethylolpropane as crosslinking agent,and isophorone diisocyanate as curing agent. The binder film was characterized by FTIR, DSC and XRD. Because of the introduction of PEG,the tensile strength of GAP/PEG binder film was raised to 3.11MPa and the breaking elongation was 475%. With the increasing degree of crosslinking of the binder film, the vitrified temperature of soft segment in the binder film decreased after an initial increase. The DSC and XRD results show that the GAP/PEG binder film is an amorphous polymer and the initial decomposition temperature of copolymer was 183℃.