In this work, based on the molecular dynamics simulation method of reaction force field (ReaxFF), the pyrolysis reaction process of Green River oil shale kerogen in the presence of montmorillonite was studied, and the product distribution of pyrolysis at different temperatures and the characteristics of non-bonding interaction between minerals and organic matter were analyzed. By comparing the product distribution characteristics of the system with montmorillonite and without montmorillonite during the heating process, it showed that montmorillonite had a strong promotion effect on the pyrolysis of kerogen, and lowered the pyrolysis temperature and widened the temperature span of the pyrolysis process, and the presence of montmorillonite resulted the increase of light oil fraction and the decrease of heavy oil fraction in the pyrolysis reaction of kerogen. The results of thermostatic simulations at a range of characteristic temperatures indicated that the addition of montmorillonite increased the yield of small molecular fragments and inhibited the polymerization of large molecular fragments at high temperatures. Montmorillonite for promoting kerogen pyrolysis was initiated by the adsorption effect, which was reflected in the presence of large non-bonding forces between kerogen and montmorillonite, dominated by VDW interactions. The simulation results showed that in contrast to the fragments of C18H30, C18H38, C20H42, C45H60O of kerogen, there were more significant non-bonding interactions between montmorillonite and fragments of C75H118O5N4, C102H167ONS2, C367H550O10N10S2, with the strongest interaction force in the fragment of C367H550O10N10S2 with montmorillonite.