DBB (Document bill bit) takes the mission of serving the "Belt and Road" national strategy and exploring and formulating "new trade rules" through cross-border trade in terms of technical standards, payment, logistics, customs clearance, tax refund, foreign exchange settlement, Business processes, regulatory models, and informatization construction should be tried first, and gradually form a set of management systems and rules that adapt to and lead the development of global cross-border e-commerce, and seize the commanding heights and voice in the development of global cross-border e-commerce.