The invention discloses a method for fast detecting the yield of biological surfactants. The method comprises the following steps: culturing microorganisms to obtain microorganism fermentation liquor; preparing supernatant; determining absorbance values A640 and A550; calculating color comparison response values according to the changes of the absorbance values; quantifying the yield of the biological surfactants according to the color comparison response values of fermentation samples by establishing a standard curve of the concentration of the biological surfactants and the color comparison response values, and determining the yield of the biological surfactants. The color comparison process of the method disclosed by the invention can be performed in an elisa plate of a microplate reader, the dosage of reagents is small, the cost is low, the detection speed is high, the detection number is large, and the detection efficiency is effectively improved, so that the method can be widely applied to the detection field of the biological surfactants.