With the continuous increase of output of primary aluminum,the output of aluminum slag is also increasing.The recy-cling of aluminum slag is imminent because the continuous accumulation of aluminum slag is easy to bring great environmen-tal problems.At present,using aluminum slag as the main raw material to produce coagulant is a way of resource utilization of aluminum slag.Coagulants produced from aluminum slag mainly include poly aluminium chloride （PAC）,aluminum sulfate,aluminum chloride,etc.The main production methods include acid solution method,preparation of calcium aluminate method,alkali solution method,etc.The current situation of aluminum slag was introduced briefly and the types and processes of producing coagulant from aluminum slag were summarized in this paper.The process of producing PAC from aluminum slag was mainly described.Compared with the traditional PAC production process,the production of PAC with aluminum slag had low cost,energy saving in the production process,full combination of aluminum slag and waste hydrochloric acid,and hydrogen with high added value was also produced in the production process,so as to further improve the economic benefits.Therefore,the traditional coagulant production enterprises would face the severe challenge of aluminum slag recycling.