The research progress of iron-based catalysts for Fischer-Tropsch to olefins(FTO) from syngas was reviewed. The process of reduction and activation was summarized, the active phase was distinguished, and the influence of carrier on the FTO reaction was discussed. Iron-based catalysts have attracted much attention due to their advantages such as low cost, easy availability and wide operating temperature range. However, many disadvantages such as complex phase, uncertain active phase and the need to improve the reaction performance are also the main problems. The activation process is directly related to the atmosphere, and the overall reaction trend is progressive from the surface to the bulk. The active phase FeCx is formed in the surface of the catalyst, and the reaction of ε-Fe2C→ε'-Fe2.2C→χ-Fe2.5C→θ-Fe3C gradually occurs with the temperature and reaction in CO containing atmosphere. θ-Fe3C has been reported to have good FTO reaction performance. In this paper, the research progress on the activity and active phase of Fe-based FTO catalysts in recent 10 years is briefly reviewed, and the regularity knowledge in these studies is sought in order to provide help for the study of the reaction performance of Fe-based catalysts for FTO reaction in the future.