The invention discloses a method and a device for a chlorine ion penetration test of a non-conductive coating. The method comprises the steps of: respectively connecting a metal base test sample and an auxiliary electrode with the two poles of a power module, wherein the metal base test sample is in contact with the electrolyte in an electrolytic cell and has a non-conductive coating on the surface; when applying positive voltage to the sample, indirectly detecting the rate that the chlorine ion penetrates the coating to reach the metal base through detecting the current; upon the completion of once current measurement, alternately applying positive pulse voltage and negative pulse voltage to the sample by the power module so as to accelerate the coating penetration of the chlorine ion; and carrying out the chlorine ion penetration test on the non-conductive coating by orderly repeating the steps. The method and the device can precisely measure the quantity of the chlorine ions penetrating the coating to reach the surface of the metal base through precisely measuring the current generated by the chlorine ion having electrolytic or electrochemical reaction, and generate a chlorine ion impact effect on the coating to accelerate the penetration of the chlorine ion and shorten the measurement time.