On June 25, Fan Zhiyong, a researcher at the National Development and Strategy Institute of Renmin University of China, and Zhang Dongying, a graduate student at the School of Economics of Renmin University of China, jointly issued a document, "Can digital currency completely replace sovereign currency? The article said that economic development requires more money, but from a global perspective, the amount of gold depends on the speed at which humans exploit gold. When the mining speed of gold could not meet the needs of economic development, human society finally chose to abandon the gold standard with gold as the main currency. A necessary condition for a digital currency to replace money is that its quantity can increase with economic development. If you don't have this feature, from the perspective of whether you can replace the currency, whether this digital currency is Bitcoin or Libra, there is no essential difference between gold and gold. The problem that gold can't be solved as a currency can't be solved by digital currency; the dilemma facing gold, digital currency will also face. Although the credit currency issued by the current sovereign countries has various drawbacks, its magical place lies in the fact that the central banks and financial systems of various countries can meet the needs of economic development in accordance with the needs of economic development to create a currency that is “out of nothing”.