A complex electrokinetic decontamination equipment is disclosed, which removes a radionuclide from contaminated soil with a high efficiency, using a combination of a washing decontamination method performed in an electrokinetic unit using electrolyte and an electrokinetic decontamination method performed by the electrokinetic unit. pH values in an anode chamber and a cathode chamber are optimally controlled by a pH control unit, thereby reducing quantity and size of metal oxide particles. In addition, a water level of the electrolyte in the electrokinetic unit may be automatically controlled by an electrolyte supply controller.