At present, banks mainly provide remittance, collection and letter of credit in international business. There are credit and exchange rate risks, low efficiency and high cost. In addition, most banks use their own credit to intervene in international settlement, which is easy to form their own contingent liabilities and reduce the quality of their balance sheets. Banks should actively promote the innovation of international settlement business based on blockchain technology, build a new system of international settlement business, and provide safe, stable, low-cost and efficient international settlement business.

? Blockchain technology can be divided into three different forms: public chain, alliance chain and private chain. Blockchain technology applied to bank international settlement business belongs to alliance chain. The new business system has three types of nodes: lightweight nodes, full-scale nodes and miners' nodes, which correspond to three types of participants: traders, regulators and banks. The rights and obligations of three different types of nodes are different. Lightweight nodes are the most important users in the business system. They propose transactions during the whole system operation, and only keep the data information related to their own transactions. As the supervisor in the business system, the number of all nodes is much less than that of lightweight nodes. These nodes keep complete blockchain transaction data for the supervision and management of cross-border trade. Miner node, as the core node of the whole system, is the founder and maintainer of the whole system. In the business system, miner node is mainly responsible for verifying the authenticity of transactions, packaging transactions into blocks, linking them to the main chain after verification, and providing services needed in the transaction process.

? The international settlement business system established by banks based on blockchain technology does not simply apply blockchain technology to the current international settlement business, but organically integrates the two and integrates the bank's business operations based on international settlement business. Extend the scope to the forefront, build a new international trade model based on blockchain technology, and design a reasonable and orderly operation process.