This article introduces a novel scalable multishard Byzantine fault tolerance ( Shar BFT) consensus protocol combined with a blockchain sharding optimization scheme. Shar BFT builds upon the classic BFT state-machine replication approach and extends it into a hierarchical multishard prototype to enable scalable and concurrent Byzantine consensus. This prototype enhances scalability and bolsters the security of global consistency in comparison to existing protocols. Moreover, Shar BFT employs a novel consensus voting mechanism based on the threshold signature scheme, resulting in linear message communication complexity and optimized consensus operations. In additional, Shar BFT integrates a sharding optimization model (SOM) to enhance consensus efficiency in dynamic system environments. The proposed SOM aims to minimize the average consensus latency while ensuring security and scalability. This article presents experimental results conducted in a real-world cloud environment, illustrating significantly improved performance.</p