The Practical Byzantine Fault Tolerance (PBFT) algorithm is a well-known consensus algorithm used in distributed systems. However, it has limitations in terms of performance and fault tolerance.This paper proposes an improved PBFT algorithm called GR-PBFT, which is based on the Short Group Signatures mechanism. Firstly, we introduce the Short Group Signatures mechanism, which involves adding nodes to the group and allowing the master node to verify messages signed by each member. Once enough signatures are collected, the master node generates the commit message. Replica nodes can then verify the commit message and synchronize the state information, thereby enhancing the interaction between the preparation and commit phases and reducing communication complexity. Secondly, we design a mechanism for dynamic node joining and exiting to improve system performance and scalability. Finally, we verify the performance and fault tolerance of the GR-PBFT algorithm through theoretical analysis and large-scale simulation experiments on the Fabric platform. The results show that GR-PBFT achieves a maximum 49.6% improvement in throughput, a 45.5% reduction in latency, and a 32% improvement in transaction success rate compared to PBFT. Particularly, when the number of nodes exceeds the threshold, PBFT performance drastically declines, whereas GR-PBFT remains relatively stable, demonstrating better performance and reliability.