Abstract: In this work,the effects of trace elements(Fe²⁺,Co²⁺,Ni²⁺)on anaerobic co-digestion of wheat straw and chicken manure were investigated by Batch experiments. The results show that the optimum concentrations of Fe²⁺,Co²⁺and Ni²⁺are 210,32 and 32 mg/L respectively.The methane yield and CODs removal can be significantly（p＜0.05）improved under the appropriate concentrations of trace elements(Fe²⁺,Co²⁺,Ni²⁺). When under optimal condition of Fe²⁺=210 mg/L,Co²⁺=32 mg/L,and Ni²⁺=32 mg/L,the methane yield are 322.21,331.19 and 357.10 mL/（g·VS）respectively,which is increased significantly（p＜0.05）by 31.33%,34.99%and 45.54%compared with the control group of 245.35 mL/（g·VS）. The CODs removal is 61.83%,57.01% and 63.63% respectively. The order of trace elements to enhance methane is Ni²⁺＞Co²⁺＞Fe²⁺. The highest cumulative methane yield and the highest CODs removal are recorded by Ni²⁺. The pH of all experiments are stable within the appropriate range during anaerobic digestion.