Starting from the multi-amine， hydroxy polybutadienes （AEHTPB）， multi-cyano， amine polybutadiene （AEHTPB-CN） was synthesized through appropriate synthesis strategies. The structure of the product was characterized via FT-IR and ¹H NMR， and its physicochemical properties such as viscosity， glass-transition temperature， hydroxyl value， and amine value were also determined. The effect of AEHTPB-CN on the mechanical properties of binder system was investigated via tensile tests， and the performance of the resultant propellant with AEHTPB-CN/HTPB mixture as a binder was explored. The results showed that the cyano groups in the AEHTPB-CN molecule could form hydrogen bonds with the urethane groups， which increased the physical crosslinking density of the elastomer and effectively improved the tensile strength. The propellant level study indicated that the AEHTPB-CN had a good bonding and burning rate inhibition effect on HTPB propellant. At room temperature， compared to HTPB-based propellant， the propellant containing AEHTPB-CN （5-8wt.%） were 35.4%-43.3% larger in tensile strength， 62.0%-91.3% higher in elongation， and the burning rate was reduced by 10.5%-11.4%.