The reduction of organic matter in the sediment is key to solve the issue of black odor river. Fenton (Fe^{2 +} + H₂O₂) reagent is effectively in the treatment of organic contaminated water or soil. Fenton reagent has been also found to remove the coloration and turbidity of black odor water effectively. But the research on the treatment of organic matter in sediment by Fenton reagent has not been reported until now. In order to explore the oxidation effect of Fenton reagent on the sediment of black odor river, in this study, Fenton reagent was used to treat black odor river sediment. The changes of sediment characteristics were investigated during the oxidation process, also the release of pollutants from the sediment was analyzed. In addition, the treatment of the sediment by H₂O₂ system (without Fe^{2 +}) was compared with Fenton treatment. The results showed that under the condition of T=28℃, input (H₂O₂) =20%Q (Q is the theoretical dosage to mineralize completely organic carbon in sediment), the molar ratio of Fe²⁺ to H₂O₂=0.5∶1, the Fenton treatment significantly increased the redox potential of the sediment and overlying water, and had a strong oxidation efficiency for organic matter in black odor sediment. During Fenton treatment, the removal of acid volatile sulfide, total organic carbon, and total organic nitrogen were 70.13%, 22.14%, and 87.60%, respectively. A substantial amount of ammonium nitrogen and nitrate nitrogen were produced. Due to the presence of iron, the concentration of soluble reactive phosphorus in the sediment was greatly reduced. Compared to Fenton treatment, the oxidation rate of H₂O₂ system was slower, and the improvement of redox potential in the system was not obvious. The release of organic acids and ammonium nitrogen to the overlying water during the Fenton treatment should be paid attention to. It is suggested that the post-treatment of the overlying water, such as biological methods, should be used to obtain the ideal repair effect.