The explosive properties of mixtures of aqueous hydrogen peroxide (H2O2) and working solution (WS), and the main components of the working solution (1, 3, 5-trimethyl benzene(TMB), trioctylphosphate (TOP)) were investigated by the drop weight test. The explosion range was interpreted by thermal calculation, and the calculated results agreed well with the experimental test. The explosion mechanism of the TMB/H2O2 mixture is the partial oxidation of TMB by H2O2, which is qualitatively obtained by analyzing the gaseous and liquid products of the TMB/H2O2 mixture after explosion. Finally, a proposed explosion mechanism was suggested. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.