Montmorillonite, a kind of nano-mineral, is potentially useful for a cigarette additive because of its catalytic capability and non-toxicity. In this research, we used thermogravimetric analysis combined with Fourier transform infrared spectroscopy spectrometry (TGA-FTIR) to study the effect of montmorillonite content to the pyrolysis and combustion behavior of tobacco on the basis of the mass loss of montmorillonite-tobacco mixtures and the FTIR spectra of the evolved gas. The results showed that the addition of montmorillonite would decrease the total amount of the most evolved gas in both argon or air especially for alkanes, CO2, carbonyl compounds, alcohols, and phenols and ethers, and make the release temperature of various gas products (like alkanes, CO, etc.) shift to a higher one. Montmorillonite had little effect on the temperature region of pyrolysis, but significantly influenced the combustion of the mixtures making the oxidizing reaction occur at a lower temperature, which demonstrated the catalytic capability of montmorillonite for the combustion of tobacco. The relevant results will provide the basis for montmorillonite as a cigarette additive to reduce the hazards during cigarette smoking, and broaden the utilization of montmorillonite resources.