To study the effect of hexogen (RDX) on the explosion characteristics of aluminum powder and aluminum powder/nitromethane mixed fuel, a 20 L spherical explosion experiment apparatus was employed to perform explosion characteristics experiments on special blended fuels. The experiment measured the explosion pressure, maximum slope of pressure and explosion duration of different blended fuel-air compound under light-concentration and simultaneously measured the lower flammable limit of the mixed fuel. The results showed that as the RDX mass fraction increases, the maximum slope of pressure and maximum pressure of RDX/aluminum powder both first increase and then decrease. When the mass fraction is 40%, the pressure reaches the maximum value of 1156.17KPa. The explosion duration has the contrary law. The explosion pressure of the RDX/aluminum powder/nitromethane mixed fuel continuously decreases, and the rate of the maximum pressure rise first increases, then decreases and finally increases. The law of explosion duration is completely opposite to that of the maximum slope of pressure. The lower flammable limit continues to increase with increasing RDX mass fraction. The lower flammable limits of RDX/aluminum powder and RDX/aluminum powder/nitromethane mixed fuel were increased from 74.93 g . m(-3) and 122.51 g . m(-3) to 226.88 g . m(-3), respectively. When the RDX has less content, RDX can suppress the reaction of the blended fuel. At the same time, through the analysis of composite particle/blends in the dispersion system, the explosion characteristics of the mixture are compared and the experimental results are explained. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.