Abstract: In this work, the reaction mechanism of DRM catalyzed by NiCo diatomic cluster was studied by density functional theory. Based on our studied that the minimum energy reaction path was found for four steps: CH₄ dissociation, CO₂ dissociation, oxidation of intermediates C* and CH*, and generation of H₂ and H₂O. Finally, the energetic span model was applied in the cycle reaction to obtain some kinetic information. At 298 K, it is hard to generate C* during the methane dehydrogenation process. At 913 K, the determining intermediate changes from IM1-1 to IM6-1, and the determining transition state changes from TS78-1 to TS56-1 of dehydrogenation of methane; Because of the reduction of energy spans, the elimination of C* and CH* are accelerated. This work can understand the mechanism of DRM catalyzed by NiCo diatomic clusters, which can provide theoretical reference for the experimental development.