The consensus mechanism is how to reach a consensus among all the accounting nodes to determine the validity of a record. This is both a means of identification and a means of preventing tampering. The blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and strike a balance between efficiency and security [16]. The consensus mechanism of the blockchain has the characteristics of "minority obeys the majority" and "everyone is equal", in which "minority obeys the majority" does not completely refer to the number of nodes, but also the computing power, the number of shares or other computers that can be compared. Feature amount. "Everyone is equal" means that when a node meets the conditions, all nodes have the right to give priority to the consensus result, which may become the final consensus result after being directly recognized by other nodes. Taking Bitcoin as an example, the proof of work is used. Only when more than 51% of the accounting nodes in the entire network are controlled, it is possible to forge a non-existing record. When enough nodes join the blockchain, this is basically impossible, thus eliminating the possibility of fraud