According to the requirement of propellant binder, a series of novel segmented thermoplastic polyether polyurethane elastomers (TPU) based on tetrahydrofuran-ethylene oxide copolyether (PET) as the soft segments and 1, 3-bis(isocyanatomethyl)benzene (XDI) extended with hydroquinone-bis(β-hydroxyethy)ether (HEQQ) as the hard segments were synthesized to study the relationships between morphology and properties. The experimental techniques utilized were dynamic rheological behaviors, FTIR, WAXD, DMA, GPC and the miscibility with nitrate ester. The results show that the storage modulus(G′), loss modulus(G″)and the complex viscosity(η^*) of the blends increase gradually with increasing fraction of hard segment content, and the TPU has a higher molecular weight with polyurethane characterization and typical microphase separation, and exhibits excellent the complex viscosity of TPU with 45% hard segment contents to meet requirements of propellant in terms of lower T_g of soft segments, good miscibility with nitrate ester, while the strain decreases WAXD results indicate that all elastomers are completely amorphous at all levels of hard-segment concentration.