To decrease the mechanical sensitivity of hydroxyl terminated polybutadiene(HTPB) propellant with high burning rate, the effects of liquid ferrocene combustion catalyst (EMT) content, particle size and ratio of oxidant AP on the mechanical sensitivity of HTPB propellant with high burning rate were studied. The correlation between thermal decomposition property and mechanical sensitivity of AP/EMT system was studied by means of DSC-TG thermal analysis and mechanical sensitivity test. The fraction and impact sensitivity of the propellant slurry increased with the increase of fine AP content or the decrease of fine AP particle size. The decomposition rate constant and heat of AP at high temperature was increased by EMT, which explained the increased mechanical sensitivity of the high burning rate propellants. The mechanical sensitivity of the propellant might be reduced by reducing content of EMT. Synergistic effect was not found between the amine salt desensitizer of GZJ-01 and electronic conductive polyaniline DBJ-01 on decreasing the mechanical sensitivity of high burning rate HTPB propellant. The mechanical sensitivity of the high burning rate propellants can be decreased by coating with fine AP and replacing EMT with GRCJ.