The root chain is an underlying infrastructure that uses blockchain technology to trace the source of data and information generated in the process of social and economic collaboration and pan-financial activities, register and confirm rights, and realize data transactions. It traces the entire process of information data through the dual dimensions of time and space, and based on this, realizes intelligent contracts trusted by multiple parties, and finally realizes credit value-driven business. The Root Card (BlockChain Source Token, BSTK) is not only a settlement tool in the general economic system, but also assumes the dual interactive identity of technology and economy in the link closely integrated with the blockchain.