Water, algae and sediment were sampled in the Zhushan Bay of the Taihu Lake, where partial black and odorous water frequently occurs, and incubated as the following combinations: sediment-water-algae, water-algae and sediment-water. Physical environmental indicators, blackening and odorous matter, and conventional indicators of the three water samples were monitored to reveal the influence of sediment on the formation of algae-induced partial black and odorous water. It was shown that sediment would make black and odorous water occur ahead of time. On the one hand, sediment promoted the formation of dimethyltrisulfide（DMTS） and further transformation. On the other hand, sediment promoted the formation of inorganic sulfur compounds and increased the concentration of sulfide and Fe2+ in the overlying water, which made the water turn black ahead of time and aggravated the water black. During the period of water blackening, sulfide and Fe2+ concentration increased by 0.63 mg/L and 0.10 mg/L in the sediment-water-algae sample, compared with the water-algae sample. The massive accumulation and death of blue-green algae made a strong anaerobic reductive environment, which induced nutrients in sediments to be released to the overlying water, making the water environment deteriorate sharply.