The invention discloses a device for embedding and extracting a printed digital watermark. The device comprises a watermark embedding machine, a watermark extracting machine and a key packet, and the device is characterized in that the watermark embedding machine is internally provided with a picture reader-writer, an embedding control mechanism and an embedding mechanism, the watermark extracting machine is internally provided with the picture reader-writer, an extracting control mechanism and an extracting mechanism, wherein, the picture reader-writer is shared by the watermark embedding machine and the watermark extracting machine; a first output terminal of the picture reader-writer is connected with a first input terminal of the embedding control mechanism, and a first input terminalof the picture reader-writer is connected with a first output terminal of the embedding control mechanism; and a sixth input terminal of the embedding control mechanism is connected with a first output terminal of the key packet. The device can quickly embed a watermark in and extract the watermarks from a printed picture, and extract the intact watermark after printing, scanning and geometric deformation of the printed picture embedded with the watermark, and has higher safety.