Abstract: Fischer-Tropsch synthesis (FTS) is the key technology of indirect coal liquefaction. Iron-based catalysts are commonly used. Due to the complexity of phase transition and the difficulty of in-situ characterization, density functional theory (DFT) has become a necessary means to study the adsorption and reaction of surface species on iron-based catalysts. In this review, the formation of different iron carbide phases and the adsorption properties of surface species were discussed based on the surface chemical properties of iron-carbon compounds. Then, the elementary reactions involved in the current DFT calculation research are briefly described. The research of chain initiation, chain growth, and chain termination under different mechanisms is summarized. Combined with the experimental research progress, the regulation mechanism of the promoters on the structure and performance of iron-based catalysts was reviewed. Finally, the existing problems of iron-based catalysts are summarized. The role of surface carbon in the reactions and the effects of various phases are prospected combined with recent results.