An explosive model is proposed for the calculation of the stationary velocity in mixtures of air and combined fuel consisting of various gaseous hydrocarbons. The required equations are obtained from a consideration of the flame-front structure on the basis of the thermal diffusion theory. In contrast to known relationships, the proposed model does not contain any ambiguities in the equation for the heat-release rate during combustion of hydrocarbons. The calculations were performed for methane-hydrogen-air mixtures. The model describes the basic qualitative results of experiments on the steady propagation of laminar combustion and provides acceptable quantitative agreement with the experiments with gaseous hydrocarbons-air mixtures.