Allyl poly (ethylene glycol) block copolymer(PEG-PGA-PAGE)was synthesized by cationic ring opening polymerization using polyethylene glycol (PEG) as initiator, BF3•Et2O complex as catalyst, glycidyl ether (GA) and allyl glycidyl ether (AGE) as monomers. The product structure was characterized by FTIR and 1H NMR. The mechanical properties and thermal properties of the two elastomers (peg-pga-page-1 and peg-pga-page-2) prepared by curing binders prepared by adding GA and AGE separately and simultaneously with terephthalobisnitrile oxide were investigated. Results show that the binder can be cured at room temperature, the cured elastomer peg-pga-page-1 prepared by subsection addition of GA and AGE has better mechanical properties and thermal properties, the tensile strength of 0.948 MPa, the elongation at break of 89.32%, shaw hardness of 23.8 Ha, the storage modulus of 361.05 MPa, Tg is - 41.85 ℃, the contact angle is 74 ℃. Room temperature curing improves the mechanical properties and thermal stability of elastomers and is expected to be used in composite solid propellants.