The invention discloses a Na<+> and Cl<-> ion purification system. The Na<+> and Cl<-> ion purification system is characterized in that a sodium chloride solution in a special positive displacement pump is sampled through a sodium chloride purification tank, a sample is sent to an integrated laboratory, concentration of each substance in the solution is analyzed, then analysis data are sent to a purification controller, and flow of an ion purification agent is controlled. The Na<+> and Cl<-> ion purification system has the advantages as follows: 1, a production process is optimized, the automation degree is high, the operation is simple and convenient, and control is easy; 2, the concentration and mass of a chlor-alkali solution are guaranteed; 3, Ca ions, Mg ions and sulfate ions are processed separately, the operational flexibility of the system is high, the range of application to salt varieties is wide, stable quality of purified brine can be guaranteed sufficiently, and optimization of the operation of an electrolytic bath is facilitated; 4, an inorganic purification agent is adopted to replace an organic purification agent, so that organic polymer substances are prevented from entering the electrolytic bath and adverse effects caused by entering of the organic polymer substances are avoided.