The invention discloses a banknote authentic identification method and a banknote authentic identification device. The banknote authentic identification method comprises the steps of: acquiring image data of a reference medium according to preset constant current source parameters and first AD register parameters, so as to obtain dark data; acquiring image data of the reference medium according to first constant current source parameters and the first AD register parameters, so as to obtain bright data; acquiring banknote image data according to first constant current source parameters and the first AD register parameters, and correcting the banknote image data according to the dark data and the bright data, so as to obtain corrected image data; and identifying counterfeit currency according to the corrected image data. The banknote authentic identification method and the banknote authentic identification device solve the problem of poor contrast of banknote acquired images caused by factors such as stability of an infrared light source and difference of the CIS image sensors during the actual identification of banknotes, and improve the identification precision of the banknotes.