Cl^- has been high chlorine toxicity to growth of the plants,and the content of Cl^- in hot-dip galvanized FeCl₂ sludge is very high,so it can not be directly disposed as general waste.In this experiment,Cl^- in FeCl₂ solution was removed by vacuum reactive distillation.At the same time,HCl gas was formed by hydrolysis of FeCl₂ and taken out by vacuum distillation,the Fe（OH）₂ was oxidized to Fe（OH）₃ by air during aeration.And then ferric oxide hydrate（Fe₂O₃·nH₂O） was obtained by filtering and drying.The removal of Cl^- from FeCl₂ solution was designed as 3 factors and 4 levels to carry out orthogonal tests,and the single factor tests were studied.The optimum technological conditions for removal of Cl^- from FeCl₂ solution by vacuum reactive distillation were as follows：FeCl₂ concentration was 1.50 mol/L,heating temperature was 75 ℃,reactive distillation time was 120 min and vacuum degree was 0.06 MPa.Under the conditions,the removal efficiency of Cl^- was up to 85.5%.When the optimum technological conditions were applied to removal of Cl^- from hot-dip galvanized FeCl₂ sludge,the removal efficiency of Cl^- reached 84.0%.