Relating to the technical field of industrial circulating cooling water treatment, the invention discloses an electrochemical circulating cooling water purification device. The device comprises a descaling box, an anode group, a cathode group and a cathode treatment unit; the top end of the descaling box is open, the descaling box is equipped with water inlets and water outlets, and a first fixedplate and a second fixed plate are arranged on two sides of the descaling box respectively; the anode group and the cathode group are located in the descaling box, and are alternately arranged at intervals along the axial direction and radial direction of the descaling box; the cathode treatment unit comprises a first support frame, a second support frame, a cleaning frame, nozzles, a scraper, a first lifting unit and a second lifting unit. The invention has the beneficial effects that: the device can meet high-flow water purification, and at the same time cleans the water scale generated in the purification process, and also the equipment operation is simple.