Adsorption of a two-component gas mixture of acetone and methylbenzene was tested in a fixed-bed apparatus, and a coupled model of heat and mass transfer was developed according to the theory of Soret and Dufour effects. The numerical simulation results agreed well with the experimental results. Using this mathematical model, the coupled effects of heat and mass transfer were studied in a fixed-bed adsorption simulation, and numerical analysis results were used to discuss the influences of heat transfer coefficients, mass transfer coefficients, and the coupled effect of heat and mass transfer on the fixed-bed process. These results show that heat transfer coefficients have little effect on mass transfer. In contrast, mass transfer coefficients have some impact on heat transfer. The mass transfer effect caused by the temperature gradient is more obvious than the heat transfer effect caused by the concentration gradient.