One of the goals of “Industry 4.0” is to build traditional factories into intelligent ones. With the emergence of intelligent factories, traditional network security cannot meet the needs of enterprises and users. In view of the security risks in intelligent factories and their products, such as proneness to privacy disclosure, this study proposes an ultra-lightweight authentication scheme suitable for intelligent factory systems by combining the RFID technology with the Blockchain technology. The scheme combines the classic RFID technology with the emerging Blockchain technology to reduce the amount of calculation under the condition of ensuring security. It meets the security needs of users with the mechanism of Blockchain decentralization. Based on the bidirectional authentication mechanism in RFID, it can resist common attacks and has high security and computing advantages.