Abstract: Light FCC naphtha (LCN) caustic extraction technology developed by SINOPEC Research Institute of Petroleum Processing was adopted in Nanyang Wax Fine Chemical Factory of Henan Oilfield. The results of operation more than one year show that the removal of mercaptan from LCN is nearly 100%. The production is stable and the product can meet the requirement of national IV phase gasoline standard. After regeneration and reverse extraction process, the caustic liquor almost no longer contains mercaptan sodium and disulfide, thus long-term effective use of caustic liquor could be realized with zero discharge of caustic liquor residue.