Taking Panggezhuang town,Daxing district sewage treatment plant's composting sludge,raw sludge,and Tongzhou local mellow soil as an example,This paper explores the dynamic changes of the sludge mixed soil leachate index.The results show that,the pH of mixed soil was reduced,and the soil total nitrogen,total phosphorus content of mixed soil were increased,also increased soil heavy metals As,Cd,Ni,Cu,Pb content,the heavy matal Pb in raw sludge series leachate maybe takes the most important part in polluting t...