Method for improving cell internal and external electron transfer efficiency and electricity generating performance of microbial fuel cell

The invention provides a method for improving the cell internal and external electron transfer efficiency and the electricity generating performance of a microbial fuel cell. Electricity generating pure bacteria are joined in the microbial fuel cell; fuels are organic substances such as glucose; a biosurfactant, namely sophorolipid, is added in the fuels, and is added according to the concentration of 20-80mg/L. The permeability of a cytomembrane can be intensified under the condition of small dosage without generating impact to the activity of cells; the resistance for electrons entering and going outside cells is also reduced; the electron transfer efficiency of the microbial fuel cell is improved; the battery power density is improved by about 3 times. The method has the advantages of capability of improving the electricity generating performance greatly, low in price and easiness in operation.