ISS establishes a decentralized global foreign exchange settlement system with the help of blockchain technology, introduces a gateway system to solve the trust problem of transfer and remittance between non-acquaintances, and the relationship between users and gateways (such as banks, third-party institutions, etc.) It is reflected in the whole system as a creditor-debt relationship, which will be stored on several servers through a distributed network, and the servers will communicate in a P2P manner to avoid various risks brought about by a single, centralized server. And through a certain encryption technology to ensure data security.