Abstract: Lime-iron salt method was widely adopted to treat the industrial wastewater with arsenic and other heavy mental ions. However, the method was seldom used to isolate the ions in ammonium sulfate solution and sulfite solution. After comparing different method and testing the method through small scale and middle scale and large scale experiments, the method could be adopted to remove the heavy metal ions in ammonium sulfate solution. The process was successfully to produce the qualified ammonium sulfate product.