Hydrogen sulfide (H₂S) produced by biofilms and sediments in sewer systems causes severe odor and corrosion problems, resulting in billions of dollars loss annually in the world. Meanwhile, methane (CH₄) production by anaerobic process in sewers may incur sewer explosion and greenhouse gas emission. Among all current sewer management measures, iron compounds have been widely used due to their effective impacts, non-toxicity, and relatively low cost. Owing to unique bio-chemical properties, the Fe (Ⅱ)-Fe (Ⅲ) iron cycle is also involved with the conversion of C, N, P and some other bioprocesses in sewer systems. In this review, the possible redox reactions in sewer systems related to bio-chemical iron cycle are comprehensively summarized, including sulfate oxidation, organic carbon oxidation, anaerobic ammonium oxidation and denitrification. Afterwards, the effects of iron compounds addition in sewer systems on nitrogen, phosphorus and organic pollutants removal are reviewed. Critical perspectives regarding future directions of iron assisted sewer management have been proposed to guide further research. This review is expected to provide instructive insights into the function of bio-chemical iron cycle in sewer systems.