HyperLedger Fabric is an open-source consortium blockchain that has received a lot of attention. Since the existing blockchain sharding method is not suitable for the three-stage transaction model of Fabric, and there is the problem of hotspot access caused by coarse sharding granularity, a fine-grained key-value state sharding method based on Fabric is proposed. First of all, the cross-shard transaction processing of Fabric under key-value state sharding is designed in detail, and a cross-shard sequence node and a two-stage submission process are introduced to efficiently ensure the consistency and atomicity of cross-shard transactions. Then, in view of the problem that fine-grained sharding may lead to an increase in the probability of transaction cross-shards and thus affect performance, a heuristic transaction proposal routing table is proposed to reduce the cross-shard data read requests of transactions in the pre-execution stage and lower the consumption of computing and network resources. Finally, the improved sharding scheme and performance test are realized on the Fabric simulation system. The experimental results show that on the basis of improving the performance of Fabric, this method effectively solves the hotspot access problem and the performance degradation problem under the high proportion of cross-shard transactions.