The invention discloses a block chain network node load balancing method based on PBFT, the method is realized based on an alliance chain platform-super account book Fabric, and the system is dividedinto a web layer, a business layer Fabric-sdk-go, an intelligent contract layer namely a chain code layer, and a Fabric namely a block chain storage layer. According to the invention, a main node carries out transaction legality judgment, verification, hash calculation and the like. When a large number of transactions arrive at a main node at the same time, the workload of the main node is very large, the other nodes are in an idle state, and when block information is broadcasted, the large number of transactions can cause too large block output bandwidth of the main node and too heavy load, which is an important factor influencing the performance bottleneck of a block chain system. The load balancing method solves the problem, a part of work of the main node is completed by other nodes, the compressed transaction information is broadcasted, the network exit bandwidth is reduced, the transaction throughput of the system is improved, and meanwhile, the safety and the error-tolerant rateof the system are still ensured.