In order to improve the mechanical strength of polymer bonded explosive (PBX) explosive carrier, the polyurethane elastic material was introduced into the explosive binder system to design the high strength carrier of polyether/polyester binder. By adjusting the proportion and molecular weight of polyols and the type of curing agent in the preparation of polyurethane elastomer, the curing rate performance of the material was analyzed by rotary rheometer and multi-functional universal material testing machine, and the influence of cured polyurethane elastomer on the mechanical strength of hydroxyl-terminated polybutadiene (HTPB) binder system was analyzed. The results showed that the tensile strength of PCL _ PTMG polyurethane elastomer was related to the curing rate of curing agent; the change of polyester polyether molecular weight had little effect on the tensile strength of elastomer; when the ratio of polyester polyether was 4:1, the tensile mechanical strength of elastomer was the best; polyurethane elastomer increased the strength of HTPB binder system.