In order to improve the dispersion uniformity and catalytic efficiency of burning rate catalysts in solid propellant grain, NC/GAP composite spherical powders containing burning rate catalysts Fe₂O₃, CuO, CNTs and Cu₂Cr₂O₅ were prepared by internal dissolution method and their related physicochemical properties were tested and analyzed. The results show that the NC/GAP composite spherical powders containing the above burning rate catalyst have been successfully prepared by the internal dissolution process, the spherification degree is high, the dispersibility is goodand the particle size of spherical powders iscontrollable. The burning rate catalysts are compounded into NC/GAP composite spherical powders by physical blending, which haveno effect on the molecular structure of NC and GAP. In addition, the introduction of burning rate catalysts accelerates the thermal decomposition of NC/GAP spherical powders. The initial thermal decomposition temperatures of composite spherical powders containing Fe₂O₃, CuO, CNTs and Cu₂Cr₂O₅ were 10.15, 15.38, 15.42 ℃ and 13.97 ℃ earlier than that of pure NC/GAP spherical powders, respectively. It indicated that CuO and CNTs had obvious catalytic effect.