Decentralized finance is an open source technology that reaches disintermediation through decentralized layers and the elimination of centralized intermediaries in order to improve the current financial system in all aspects, emphasizing the core tenets of openness, fairness and connectivity. Take cross-border payment as an example, when a person remit money to a person in another country, they usually need to find a financial institution to complete the payment task, but it will charge a certain fee in return.