Abstract: Polyethylene dust fire and explosion accidents occur from time to time. In order to improve the safety of enterprise production, two kinds of explosion suppression powder MCA and MPP were selected and the 20 L exploding ball experimental device was used, to comprehensively analyze the effect of explosion suppression agent on the explosion characteristics of polyethylene powder from the explosion characteristic parameters, pyrolysis characteristics and explosion products. The results show that: MCA and MPP powder had a good inhibition effect on polyethylene, and with the increase in the concentration of explosion suppression and further enhancement, when 67.5% of MCA mass fraction and 60% of MPP mass fraction were added, the polyethylene powder explosion was completely inhibited. Through an analysis of pyrolysis characterisation, it was found that the addition of MCA and MPP inhibitors could slow down the oxidation and thermal decomposition of polyethylene powder, and the activation energies of the mixtures were higher than those of single polyethylene powder. At the same time, ReaxFF-MD simulation analysis showed that the inhibitors successfully attenuated the gas-phase reaction of polyethylene powder during pyrolysis at high temperatures. In addition, the inhibition mechanism was analysed by combining the explosion pressure, pyrolysis characteristics and explosion products. The study results have scientific and practical significance for the prevention and control of polyethylene powder explosion.