The heats of formation for poly(3, 3′-bisazidomethyl oxetane-3-azidomethyl-3′-methyl oxetane) (P(BAMO/AMMO)) based energetic thermoplastic polyurethane elastomers (ETPE) with different content of poly(3, 3′-bisazidomethyl oxetane) (PBAMO) and hard segment were estimated by group additivity method and combustion heats method. The effect of contents of PBAMO and hard segment on the heat of formation of ETPE. A group of P(BAMO/AMMO) ETPE-based propellants were selected by the least free energy method. The theoretical specific impulse was calculated. The maximum static state tensile stress, breaking elongation, impact sensitivity, friction sensitivity, burning rate of P(BAMO/AMMO) ETPE based propellant formulation were measured. Results show that the heat of formation of P(BAMO/AMMO) ETPE decreases as the mass of PBAMO increases or the content of hard segment decreases. The theoretical specific impulse of the preferred 15/5/20/38.5/18/3.5-P(BAMO/AMMO)/Bu-NENA/RDX/AP/Al/catalyst propellant is 2699.51 N·s·kg^-1 under the combustion chamber pressure of 10 MPa. The maximum tensile stress of the propellant is 1.22 MPa. The breaking elongation is 11.37%.The coated-solid filler can significantly reduce the mechanical sensitivity of premixed materials, making impact sensitivity H₅₀ increase by 37 cm, friction sensitivity P decrease by 36%, and burning rate pressure exponent (n) be 0.37 in the pressure range of 6 to 15 MPa.