Based on the corrosion problems induced by the chloride ingression of marine port engineering,laboratory experiments of electrochemical chloride extraction (ECE) were carried out, and then demonstration project was carried out in Zhanjiang port. This paper focuses mainly on the chosen of electrolyte and the design,installation, commissioning and operation of the ECE system, the reduction of chloride ion and the potential of steel before and after ECE. Moreover, the relationship between the total electricity quantity and residue chloride ion is studied.