Based on density functional theory and classical transition state theory, the reaction mechanism of NO reduction by H2 catalyzed by coke in hydrogen rich blast furnace was investigated. The results showed that the presence of active sites on the coke surface promoted the NO reduction reaction. Reactive oxygen species remaining on the coke edge inhibited the NO reaction after NO reduction. Both coke and H2 can release edge sites by reducing reactive oxygen species, but reactive oxygen species reduction by H2 requires a high barrier value of 634,3 kJ/mol, which is higher than that by coke.