The invention discloses an energy-saving method for electrolyzing metal manganese. In electrolytic process, an impulse power source is adopted, wherein the impulse frequency of the impulse power is 900-1200Hz, the duty cycle thereof is 40-80%, and the average current density thereof is 380-420A/m<2>. During the electrolytic process, an anode plate is an electrode plate with a plurality of concavepits, the diameters of the plurality of the concave pits are 0.5-2.5mm, the center distance between the concave pits is 2-9mm, and the depth of the each concave pit is 0.5-2.5mm. The method can improve current efficiency, and the test shows that the current efficiency is improved to more than 80% compared with the current efficiency being not more than 75%. The method can reduce the generating amount of anode mud in an anode area so as to prolong the service life of the anode plate, reduce the times for cleaning slots, obtain the beneficial effect of saving energy, and naturally and greatly reduce the cost for electrolyzing the metal manganese.