The invention provides a method for information extraction and identity authentication by identifying raster graphics. The method comprises the steps that the raster graphics are read, and obtained images are fed back; the fed-back images are automatically processed and placed in a cache; the images in the cache are analyzed and verified, so that code value information corresponding to the images is generated; information files corresponding to the code value information are found in a code value data base and extracted; the information files are decoded, so that multi-media files are formed, and the multi-media files correspond to the information files and comprise identity authentication information; the multi-media files are played, so that identity information of products corresponding to the raster graphics is obtained. According to the method, the raster graphics replace existing RFID labels and other modes, the method, the digital technique and the network technique are combined, and the method has the advantages of being low in printing cost, terminal manufacturing cost and enterprise operating cost, and achieving user inquiry mode convenience, and effectively achieves the effects of copying difficulty, low price and identifying convenience.