The invention provides a method for accelerating color printing iron corrosion by using electrochemical cathodic polarization. The method comprises the following steps of: (1) manufacturing the color printing iron into a working electrode, installing the working electrode into an electrolytic tank, wherein a reference electrode and an auxiliary electrode are installed in the electrolytic tank in advance, and assembling into an electrolytic tank system; (2) maintaining the electrolytic tank system in an anaerobic environment; (3) connecting the electrolytic tank, an electrochemical working station, an adjustable voltage-stabilized power supply and a double-pole-double-throw switch; and (4) adjusting the output voltage of the adjustable voltage-stabilized power supply so as to carry out cathodic polarization on the working electrode, measuring the electrochemical impedance spectrum of the working electrode by using the electrochemical working station, obtaining the coating resistance of the working electrode, and confirming that the coating corrosion final point is reached when the coating resistance is less than or equal to 106omegacm<2>. By utilizing the method, relatively high resolution is achieved, the degree of degradation and failure of the coating is quantitatively analyzed according to the change of the impedance response, and good foundation is established for further improving and optimizing a color printing iron machining process.