Abstract: The removal efficiency of COD and NH₃-N in aged landfill leachate by single electrode electroflocculation system with different current density and plate spacing in 120 minutes was studied. Based on the BBD response surface method, the single and interaction of current density, plate spacing and reaction time were investigated. From the point of view of optimizing the removal rate of target pollutants and the energy consumption of electroflocculation system, the construction strategy of electroflocculation was analyzed. The results show that the current density, plate spacing and reaction time were significantly correlated with the removal rates of COD and NH₃-N. The removal efficiency was positively correlated with changes in current density and negatively correlated with electrode spacing. The interaction of three factors had no significant effect on the removal of COD and NH₃-N. The maximum removal rates were found to be 87% for COD and 86.5% for NH₃-N, achieved at a current density of 80 mA·cm^-2, an electrode spacing of 5.5 cm and a reaction time of 120 min. Considering the safety, economy and environment, under the two electro-flocculation systems of long time, low current density and short time, high current density, the invention can realize the high-efficiency purification of pollutants and the low energy consumption of the electrolytic cell system.