Abstract: In order to solve the problem of single shard failure caused by sharding technology in blockchain, a multi-round PBFT verification scheme is proposed. However, the random allocation process of nodes will reduce the effectiveness of transaction verification. By analyzing this problem and comparing the current node allocation schemes of major sharding projects, a node allocation scheme based on node evaluation is proposed. This scheme marked suspected Byzantine nodes by scoring the nodes in the blockchain system, and realized the operation of joining and exiting the shard according to the identity mark, which realized a significant reduction in the proportion of Byzantine nodes in the shard and improved the verification efficiency. Through four sets of comparative experiments, it shows that the node allocation scheme based on node evaluation has higher verification efficiency and significantly improves system throughput.