Heavy metal wastewater treatment system and treatment method thereof

The invention relates to a heavy metal wastewater treatment system and a treatment method thereof. The heavy metal wastewater treatment system comprises an adjusting tank, a PH adjusting unit, an electrochemical unit, a catalytic oxidation unit, a neutralization and flocculation unit, a high-density precipitation unit and a PH callback unit, the adjusting tank is connected with the PH adjusting unit through a wastewater pipe, and the electrochemical unit is arranged on one side of the PH adjusting unit; the electrochemical unit is connected with the catalytic oxidation unit through a wastewater pipe, the neutralization and flocculation unit is arranged on one side of the catalytic oxidation unit, the neutralization and flocculation unit is connected with the high-density precipitation unit through a wastewater pipe, the high-density precipitation unit is connected with the PH callback unit through a wastewater pipe, and the electrochemical unit and the high-density precipitation unit are connected with the sl