The invention discloses a colorimetric sensing method for generating inorganic nanoparticles based on enzyme catalytic induction. The method comprises the steps: taking a frerric chloride solution, apotassium ferricyanide solution and an enzymatic solution, mixing, respectively adding the mixed solution into target solutions with known different concentrations, carrying out a reaction, quantitatively detecting by ultraviolet-visible spectroscopy to obtain the corresponding ultraviolet-visible absorbance values in all the concentrations, and thus obtaining a linear relationship between the target concentrations and the absorbance values; and adding a to-be-measured target solution to the mixed solution, detecting the absorbance value, and calculating to obtain the target concentration of the to-be-measured target solution. The method directly adopts Prussian blue as a colorimetric probe, and the constructed colorimetric sensing method has the advantages of being fast, simple, low in cost, high in sensitivity, good in selectivity and the like, has satisfactory results in application and has broad application prospects.