Soil serves as a crucial terrestrial reservoir of organic carbon, plays a significant role in mitigating climate change and ensures sustainable agricultural production. Iron oxides, as important active components in soil, are integral to the stabilization and turnover of soil organic carbon. These oxides interact with organic carbon through processes such as adsorption, co-precipitation, and other mechanisms, forming relatively stable iron-carbon complexes. Additionally, iron acts as a catalyst in the polymerization of organic carbon, facilitating the transformation of organic carbon into more stable forms via the Maillard reaction. However, these protective functions of iron oxides can be modulated by environmental factors, which may reduce their effectiveness under fluctuating conditions. During redox cycling of iron, iron oxides can also accelerate the organic carbon turnover by releasing reactive oxygen species and transferring electrons. This review provides a systematic examination of the mechanisms by which soil iron oxides influence carbon turnover and sequestration, while also exploring the reciprocal effects of organic carbon on iron cycling. This study further evaluates the role of environmental factors and key biological processes in regulating iron-carbon cycling. Particular emphasis is placed on the critical roles of mineral protection and biological activity constraints in maintaining soil carbon pool stability. Finally, the review proposes several directions for future research in the iron-carbon field. These include the verification and quantification of soil organic carbon polymerization reactions, understanding the regulatory role of soil microzone biological processes on iron-carbon coupling, exploring the trade-offs between organic carbon fixation and morphological transformation during iron redox processes, and integrating a cross-scale model for iron-carbon coupling and carbon sink potential assessment. Conducting these studies will facilitate the accurate analysis of physical-chemical-biological mechanisms of soil iron-carbon coupling and furnish insights to promote a more profound understanding of iron-carbon dynamics and formulate strategies for enhancing soil carbon sequestration.