Blockchain is a decentralized distributed ledger technology, which has the characteristics of information immutability, openness and transparency, traceability, etc. However, in the process of blockchain transactions, each node is public, which will greatly increase risk of privacy breach. In view of the above problems, this paper mainly analyzes the defects of privacy protection in fabric, studies targeted privacy protection schemes, and improves the anonymity mechanism of blockchain transactions and the access mechanism of data acquisition.