Abstract: Indoor simulation experiments covering sediment surfaces with iron, aluminum, manganese oxide and lake sand for a year were conducted to investigate the impact mechanism of metal oxidex on sediment dissolved organic matter (DOM) by three dimensional fluorescence spectrum and ultraviolet-visible spectrum. The obtained results showed that:(1) the sediment DOC content of 0-3 cm depth decreased by 8.61%, 6.27%, 22.38% and 0.44% in the samples covered with Al, Fe, Mn oxide and lake sand, respectively. (2) The tyrosine peak (peak B₁) and tryptophan peak (peak T₂) in the sediment DOM varied greatly. Three oxides significantly reduced the peak T₂ of the surface sediments DOM, and significantly increased the peak T₂ of the underlying DOM; the Mn oxide reduced the peak B₁ of the DOM, and the Fe and Al oxides increased the peak B₁ of the DOM. The two peak types decreased by covering with lake sand. (3) The coverage by metal oxides changed the structure of sediment DOM, whereas the coverage of Fe oxides enhanced its aroma, while covering with manganese oxides and aluminum oxide reduced its fragrance. However, the three oxides increased the degree of DOM and the number of functional groups, increased FI value and promoted the DOM transformation to biological sources. The results showed that the sediment surface covered with metal oxides affected the sediment DOM migration and transformation, and promoted its degradation, resulting in increments of molecular weight and humification degree.