In industrial production, a large amount of ferrous sulfate waste liquid is produced every year, and the output of iron and steel deep processing process is the largest. Ferrous sulfate waste liquid contains sulfuric acid with low pH value and metal ions such as Hon, cobalt, nickel, aluminum and chromium. Direct discharge not only wastes metal resources, but also causes serious pollution to soil and water. How to comprehensively recover ferrous sulfate waste liquid has great economic benefits for enterprises and certain environmental benefits for society. At present, the main treatment methods are neutralization treatment, chemical precipitation, crystallization precipitation, solvent extraction, microbial method and so on. According to the ferrous sulfate waste liquid produced in different production processes, corresponding treatment methods should be adopted. Because a large amount of metal sludge will be produced by neutralization method, the product market demand of crystallization precipitation method is low, the treatment capacity of solvent extraction method is low, and the treatment cycle of microbial method is long, so chemical precipitation method is the main recovery method at present The chemical precipitation method is easy to operate and does not need high-performance equipment, but there are many influencing factors in the test and the product properties fluctuate greatly. From ferrous sulfate waste liquid recovered products are mainly used in pigment industry, water treatment industry, magnetic materials industry and so on. Most products only use iron in waste liquid, but sulfuric acid and sulfur are not recovered. HOW to comprehensively recover waste liquid is a research focus. Because there are many impurity elements in ferrous sulfate waste liquid, it is very difficult to purify it, and the production cost is also high. Therefore, how to directly utilize the waste liquid is also the main research direction in the future. [ABSTRACT FROM AUTHOR]