The invention brings forward a high-precision measurement method of a scratch area and a grayscale parameter of an IC card chip. The method comprises the following seven steps: before scratches are detected, a clean scratch-free electricity purchase card chip is acquired as a standard base graph through a CCD, another clean scratch-free electricity purchase card is taken and is inserted into a card slot for a plugging test, an electricity purchase card chip to be measured is scanned through the CCD, a comparison with the base graph is made, differences are analyzed, the differences are scratch information, the scratch information is analyzed by use of a certain algorithm, and thus the purpose of quantitative detection of the scratches is realized. The method provided by the invention has the following technical advantages: the problems of inconsistent man-eye observation and evaluation standards, large manual errors and the like can be overcome through the method, based on digital image processing, by use of a BLOB algorithm, the scratch area and the grayscale parameter are calculated, and scratch degree of the electricity purchase card is accurately and quickly analyzed in a quantitative mode.