The invention discloses a cathode bus-bar configuration method of an ultra-large aluminum electrolytic cell. The total quantity of end compensating current is rated and cell bottom bus-bars adopt alternate compensation for offset, that is, the total current quantity flowing through a flue end is controlled within 100-150 kA, the current quantity of an aluminum discharge end is controlled within 80-120 kA, and the rest current on the A side bypasses the multiple cell bottom bus-bars. The routing manner of cathode bus-bars is designed accordingly, and specific parameters of cathode bus-bars of the electrolytic cell, independent compensation bus-bars, cell spacing and plant spacing are determined according to the calculated result of a magnetic fluid model. With the adoption of the cathode bus-bar configuration method of the ultra-large aluminum electrolytic cell, basic configuration of the bus-bars of the ultra-large aluminum electrolytic cell can be determined quickly, the vertical magnetic field and the horizontal magnetic field of melt can be effectively reduced, uniform distribution of the magnetic fields in the long axis direction of the cell is realized, stable operation of the aluminum electrolytic cell is realized, and the current efficiency of the electrolytic cell is improved.