The invention provides a microbial fuel cell and a method for enhancing electricity generation performance of the microbial fuel cell. The microbial fuel cell comprises a reactor, a cathode and an anode, wherein either cathode or anode is arranged on one side of the reactor, and the other electrode is arranged in the reactor; the anode is made of carbon felt, and the cathode adopts a gas electrode containing metallic catalyst; the distance between the two electrodes is 0.5-2.0 cm; the lower end of the reactor is provided with a water inlet, and the upper end is provided with a water outlet; the upper part of the reactor is provided with a sealing cover; a reference electrode slot is arranged on the sealing cover; the cathode and the anode are connected by a wire and connected with a load to form a closed loop circuit; anaerobic sludge is inoculated in the reactor, and fuel is introduced into the reactor; and 5-80 mg of microbial solvent Tween is added to every 1L of fuel. The invention has the advantages of great increase of output power, low price, small effect on environment, and easy realization.