Migration and leaching of plasticizers will severely affect the physical and mechanical properties of polymers. In this study， two new monomers， 3-（4-nitrofurazan-3-oxy-methyl）-3-bromomethyl oxetane （BrNFMO） and 3，3-bis（4-nitrofurazan-3-oxy-methyl） oxetane （BNFMO）， were synthesized by the combination of 3-nitro-4-hydroxy-furazan and dibromomethyl oxetane （BBMO）. Using hydroxy-terminated polyether （HTPE） as macromolecular initiator， three block copolymers containing azide groups were synthesizd by polymerization of BrNFMO， BNFMO and BBMO under the catalysis of boron trifluoride ether followed by azidation process. Then the detonation performance of the designed monomer structure was evaluated by quantum chemistry. Besides， the copolymerization process was optimized by the control variate method， and better copolymerization conditions were obtained. The results show that this series of novel energetic copolymers can further improve the energy level of the binders， and the intramolecular plasticizing strategy can result in energetic polymers with lower glass transition temperature （T_g） and viscosity by introducing azide groups into the polymer through the structure of azidofurazan ether， compared with directly introducing azide groups into the polymer. T_g can be reduced by 5.27 ℃， viscosity can be reduced by 4.90 Pa·s， and its thermal stability is also improved （thermal decomposition temperature （T_d） can be increased by 7.3 ℃）.