A model was developed for the gasification of a single anthracite particle in an environment of steam, carbon dioxide, carbon monoxide, methane, and hydrogene in the gasification zone of a reactor. This model consisted of the mass and energy balance equations together with stefan-maxwell relations without equilibrium assumption of water-gas shift reaction based on the shrinking core model. The gas concentration profiles within ash-layer and the temperature front profiles of particle and reaction surface could be obtained. It was found that the effect of water-gas shift reaction was significant with increasing coal conversion and the molar ratio of product gases（ψ） approached its equilibrium value(K_e) at high temperature(more then T_b=1300 K).