With the rapid development of electric Internet of Things technology, it is of great significance to build energy Internet. The identification and authentication of power IoT terminal equipment is the basis for ensuring the safe and stable operation of energy Internet. In order to realize efficient collection and security authentication of massive power terminal equipment information, this paper proposes an RFID authentication protocol for power Internet of Things, the protocol uses RFID technology and is designed based on national secret SM3 and SM4 algorithms, which not only realizes the mutual authentication between the reader and the power equipment, but also ensures the transmission security of the power communication data, and reduces the computational complexity of equipment tags. Security analysis shows that the protocol satisfies security requirements, such as untraceability, withstand replay attack, de-synchronization attack and denial of service attack, etc. BAN logic analysis further shows the protocol satisfies the mutual authentication, Performance analysis shows that the protocol has better performance advantages in tag computation, storage, traffic and database search efficiency.