The blockchain-based payment guarantee introduced in this paper is a subversive innovation for traditional third-party payment guarantee. By combining blockchain technology with bank-managed cash guarantee and credit guarantee system，fund security management and control service platform with cross-bank freezing and cross-bank payment functions via smart contract of blockchain，the client’s funds remain in the bank’s physical households or bank supervisory households throughout the process. Establish a alliance chain with the bank as the core nodes and gradually invite arbitration，notary，insurance，logistics and other institutions to join us and timely discover and deal with abnormal transaction risks through data sharing and traceability on the blockchain to ensure the safety of users’ funds.