The invention relates to a method for quickly detecting content of 5-hydroxytryptophan. The method comprises the following steps of obtaining a to-be-detected solution, dripping 1% KOH (potassium hydroxide) ethyl alcohol solution, and adjusting the pH (potential of hydrogen) value to be 9-10; adding a 0.5% 2,6-dibromobenquinone chlorimide ethyl alcohol solution, fully oscillating, uniformly mixing, standing at room temperature, detecting light absorbance at the wavelength of 606nm, and calculating the concentration of 5-hydroxytryptophan in the to-be-detected solution according to a standard curve. The method has the advantages that by utilizing the specific color developing reaction, the content of 5-hydroxytryptophan in the solid powder, extracting solution and fermenting solution can beaccurately and quickly detected, and the application range is broad; the interference by tryptophan and other amino acids, peptides and proteins can be eliminated; the good specificity, accuracy andreproducibility are realized.