"Everything derives from digit, digit composes with everything", with the development of technology and consistently improvement of humanity talent, humankind realize "Universe is made from digit, everything are digit, digit connect everything". Digital Economy, Digital Currency, Digital Life Key, Digital Cycle those which have close ties with the origin, life, and life span of humanity. That is to say, all of the humankind activities and natural principal almost relate to digit. The research on Digital Phenomenon, Digital Mystery, and Digital Values is a everlasting exploration theme for humankind.
Urban Development Union of countries along the Belt and Road Route consist of the Digital Economy Union which starting over the "Digital Economy Times" between nations and cites, thereby "Digit" play an important role in scientific research and application. The "Digital Economy" mainly relies on Internet, big data, Cloud computing, AI, and innovative thinking. The countries along the Belt and Road Route with China's cities jointly build up an interconnected Digital Economy Union, it is no doubt that trigger and largely improve the constructions on internet, correspondence and relating area in the countries along the Belt and Road Route. The Digital Economy City Union come up with the background of China propose the "5G plus New Infrastructure" in 2020, claiming that the Digital Economy from China to whole world, even to the One Belt and One Road.