An idealized extinguishing agent with two main inhibition mechanisms was designed to test the chemistry of hydrogen flame extinguishment. The One-Dimensional Turbulence (ODT) model and chemical explosive mode (CEM) analysis (CEMA) were used to perform an in-depth analysis on the role of turbulence-chemistry interaction in diffusion hydrogen/air flame. The function route of the fire extinguishment agent in diffusion flame has been analyzed. The results show that the agent can significantly reduce the CEIvl. The decrease of CEM will decrease the Da number, and lead to flame extinction. The CEMA of ODT results present that the extinction of flame is controlled by the CEM, the mixing rates and the eddy events. The results also illustrated the main inhibition mechanism in which catalytic cycles lead to the destruction of major chain carriers, H. The acting areas of variables and reactions are consistent and clearly visualized with CEMA, which proves that the CEMA is a very efficient method to identify the control variable during the combustion process. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.