In order to obtain the heterogeneity of coal, the mechanical tests were performed. The experimental results show that the heterogeneity of the mechanical parameters for coal follow the Weibull distribution. Then the model of coupled gas flow and deformation process for heterogeneous coal was presented and the effects of heterogeneity of coal on gas flow and failure of coal were investigated. The finding is that the effect of the heterogeneity of coal on gas flow and mechanical failure of coal can be considered by the model in this paper. Failure of coal has a great effect on gas flow.