Abstract: Abstract: In recent years, with the development of Chinese animal husbandry, some heavy metals have been added to animal feed to speed up the growth of livestock and poultry and prevent diseases. But most heavy metals can not be absorbed and digested, resulting in increasingly serious pollution problems of heavy metals in livestock and poultry manure, which seriously affects the resource utilization of livestock and poultry manure. In this paper, pig manure was used as the treatment object, and heavy metal cadmium(Cd) was used as the research object. Different pretreated maize stovers was added (maize stovers and pig manure C/N of 25:1). The anaerobic fermentation period is 90 days, fermentation temperature is of 35℃, inoculum quantity is of 30% fermentation raw material, total solid is of 10% and pH value is of 7. The aim of this study is to provide a scientific basis for the treatment of heavy metals in livestock and poultry manure. The result shows: 1)After the end of anaerobic fermentation, the proportion of exchangeable and reducible Cd contents in the treatment of adding maize stovers all decreased, and the proportion of oxidizable and residual Cd contents all increased. The results show that the anaerobic fermentation of pig manure and maize stovers is beneficial to convert heavy metal Cd from an effective state to a stable state. 2)The passivation effect of effective form of heavy metal Cd in the anaerobic fermentation of pig manure alone is 21.22%, the effective passivation rates of heavy metal Cd in untreated corn stalk, dilute H2SO4 treated maize stovers and NaOH treated maize stovers were 29.60%, 32.00% and 32.38%, respectively. The results showed that the anaerobic fermentation of maize stovers added to pig manure was beneficial to improve the passivation effect of heavy metal Cd. The passivation effect of heavy metal Cd in NaOH maize stovers is better. Significant analysis showed that the anaerobic fermentation of pig manure with maize stovers significantly increased the passivation of heavy metal Cd (P<0.01). The passivation effect of maize stovers treated with dilute H2SO4 and NaOH were significantly higher than that of untreated maize stovers group (P<0.05). There was no significant difference in passivation effect between NaOH treated maize stovers and dilute H2SO4 treated maize stovers (P>0.05). 3)Fourier Transform Infrared Spectrometer showed that the materials of each treatment group had similar spectral characteristics before and after anaerobic fermentation. After anaerobic fermentation, the relative intensity of the absorption peaks of the biogas residue of each treatment group decreased at 3 408-3 414 and 2 850-2 922 cm-1, indicating that the organic matter such as amide compound, carbohydrate, protein, and aliphatic compound in the biogas residue were decomposed and reduced. The absorption peak intensity at 1 642-1 653 and 1 240-1 264 cm-1 increased, indicating that the olefins, aromatic compounds and other substances in the biogas residue increased. The addition of maize stovers during the anaerobic fermentation of pig manure is beneficial to the reduction of organic matter content, the increase of humus content, and the humification degree of organic matter is better when the pig manure is added NaOH maize stovers. Adding an appropriate amount of NaOH and H2SO4 maize stovers to the anaerobic fermentation of pig manure can reduce the effectiveness of heavy metals in the biogas residue and the risk of heavy metal pollution.