The invention discloses an apparatus and a method for enhancing biodegradation of dye wastewater with micro-current. The apparatus comprises a filter box, wherein by virtue of a filter membrane, the inside of the filter box is divided into a cathode unit and an anode unit; the inside of the cathode unit is filled with activated carbon granules and is inoculated with activated sludge; a cathode electric conductor is inserted in the cathode unit; an anode electric conductor is inserted in the anode unit; the cathode electric conductor is connected to the cathode of a power supply by virtue of a lead wire, and the anode electric conductor is connected to the anode of the power supply by virtue of a lead wire; a water inlet is formed in the lower part of one side, opposite to the filter membrane, of the cathode unit; and a water outlet is formed in the upper part of one side, opposite to the filter membrane, of the anode unit. On the basis of the characteristic that dye wastewater can be degraded with microorganisms, the apparatus which can stimulate the degradation of the dye wastewater with micro-current can improve the removal efficiency of dye, shorten treatment time and save energy, and the apparatus is free from the generation of sludge or odor.