BI Token is an open digital asset exchange network. BI Token is based on multi-chain swap technology, with open liquidity sharing as its core feature, and empowers digital finance with blockchain technology. The BI Token network realizes the functions of settlement, clearing and financial asset liquidity sharing through the three-layer architecture design of Settlement Protocol, Clearance Protocol and P2P Exchange Protocol. The three-layer protocols are both interconnected and independent, and all have the characteristics of openness. BitokenSettlement Protocol is designed based on the Hash Lock principle and will support more traditional financial asset swaps. BI Token will play an important role in improving the blockchain ecology and connecting digital finance and traditional financial markets as the "lightest" and "most complete process" asset exchange infrastructure of the digital financial ecosystem.