Impressed current electrochemical chloride extraction is effective enough to eliminate the harmful chloride ion in concrete,but it has shortcomings of not applying to the prestressed reinforced concrete structure,being likely to cause the danger of hydrogen embrittlement and decrease bond stress,being inconvenient in installation construction management and needing professional personnels to operate during field desalination.The way of using sacrificial anode electrochemical chloride extraction to move out harmful chloride ion in the reinforced concrete can overcome the above disadvantages,and it is not only suitable for ordinary concrete,but also suitable for prestressed concrete.This paper studies the influence of sacrificial anode electrochemical desalting effect from three aspects including conduction time,desalination device location and sampling depth.The results show that the sacrificial anode electrochemical chloride extraction can effectively remove the chloride ion in the concrete out of the active filler material after 3 months,and at 500 mm from the anode with the highest the desalting efficiency.This method can remove harmful chloride ion out of the concrete sample,and concrete specimen surface desalting efficiency can be raised up to about 60%.