Abstract: The aim of this paper is to study the effects of simulated acid rain on the release of nutrient salts and heavy metals of sediment by reducing the pH value of overlying water from chaohu lake, so as to predict the effects of acid rain or acid wastewater on the stability of lake ecosystem.The simulated results showed that the pH value of the overlying water recovered after simulated acid rain, but the resilience of strongly acidic simulated acid rain (pH 4.0) was poor. During the experiment, the order of DO content in water was CK > the test group (pH 5.5) > the test group (pH 4.0). The simulated acid rain promoted the release of nitrogen and phosphorus in the sediment, and the content of TN and TP in the overlying water of the test group (pH 4.0) was significantly higher thanthe test group (pH 5.5) (P<0.05). Iron/aluminum phosphate were released mainly under weakly acidic simulated acid rain condition while calcium phosphate were released mainly understrongly acidic simulated acid rain condition. The biomass of Microcystis sp. was the largest of the control group, but not the two experimental groups, indicating that the simulated acid raincould inhibit the growth of Microcystis sp.. The pH value, TN, TP and Iron/aluminum phosphate were significantly correlated with the content of Pb, Zn, Cd and Cu, the four major heavy metals in the sediment (P<0.05), indicating that acid rain and nutrient salts were important factors affecting the occurrence and release of heavy metals in the sediment.