Many wire rope enterprises in Nantong used acid pickling and phosphating process. which produced much acid waste liquid containing heavy metal ions lead, iron and zinc. This might cause regional characteristic environmental pollution. The diffusion dialysis negative membrane which produced by Shandong Tianwei membrane technology company was used to treat the wire rope acid waste liquid. The result showed that this membrane could separate acid and salt effectively. The recovery of acid was over 90%. The retention rate of lead is over 70% and the retention rate of iron is over 80%. However, lead chloride crystal might precipitate, and block outlet of the treatment equipment. Thus further research and discussion were needed.