The invention discloses an on-line electrolytic mixing clarifying tank comprising electrolytic grades and non electrolytic grades or only comprising the electrolytic grades, a clarifying room of each electrolytic grade is provided with electrodes, a cathode and an anode are mutually crossed, and the cathode and the anode are used as the electrodes and simultaneously form a material-liquid flow channel. The on-line electrolytic mixing clarifying tank provided by the invention has a high electrode utilization rate and a good electrolytic reduction effect, and can quantitatively control current of each electrolytic grade.