A 20L spherical explosion testing system was used to characterize the explosion characteristics of brown coal powder and its mixing with different explosion suppressants. and the free radical reaction mechanism was studied through numerical simulation. Research has shown that sodium bicarbonate (NaHCO3) has a low decomposition temperature and a fast reaction rate in the early stages. A significant amount of phosphorous groups are produced when ammonium dihydrogen phosphate (NH4H2PO4) and melamine polyphosphate (MPP) react, consumes explosive free radicals and blocks heat transmission between coal dust, delaying and inhibiting explosion. In the explosive reaction, H and O free radicals are continually consumed during the breakdown of cyanuric acid melamine (MCA). Finally, the suppression mechanism of different explosion suppressants on coal powder explosions was revealed, and specific recommendations were made for the selection and application of explosive suppressants.