The invention discloses a scandium ion rapid determination method with nanogold being a color-developing probe. According to the method, a strong suppression function on scandium ions in a phosphopyridoxal mediated mercaptoethylamine-nanogold aggregation process is utilized to express changes of solution color and ultraviolet absorption spectral characteristics, and therefore scandium ion contentis detected. When color characteristics are observed visually, the color of a reaction system is changed from blue to purple to pink to wind red along with gradual increase of the scandium ion concentration (0-5 mu mol/L); and when the absorbance ratio A<700>/A<525> is determined, the absorbance ratio A<700>/A<525> of the reaction system is gradually reduced along with the increase of the scandiumion concentration, the A<700>/A<525> and the scandium ion concentration are in a linear relation within the range of 0.1-3 mu mol/L, and the detection limit is 0.02 mu mol/L.