AbstractAmorphous boron powder granulated with HTPB, whose particle diameter could be controlled, was prepared by mechanical mill method. It was found that amorphous boron powder could be granulated with HTPB binder to form B‐HTPB particles, whose median particle diameter (d50) and specific surface area are in the range of 125.0–431.0 µm and 0.02–0.1 m2 g−1, respectively. The B‐HTPB particles could be dispersed in the HTPB binder with relatively low viscosity compared with direct addition of amorphous boron powder to the HTPB binder. The experimental results showed that the content of boron particles in a fuel‐rich propellant could be increased by addition of B‐HTPB particles and the combustion characteristics of the fuel‐rich solid propellant could be improved.