On January 3, the Financial Times reported that traditional banknotes have higher cash management costs, and central bank digital currencies can reduce the operating costs of fiat currencies, improve payment efficiency, and facilitate cross-border payments. At the same time, in developing countries with low bank penetration and backward financial depth and breadth, digital currencies can provide the public with a more secure and liquid payment method. This payment method is endorsed by the national credit. There are no defaults or "runs" under the circumstances. Finally, the emergence of endless private digital currencies has put pressure on regulation and monetary policy. Digital currencies of central banks can enhance market competitiveness and maintain market discipline. Because the central bank has the ability to track payments to digital currencies, legal digital currencies are conducive to the supervision of illegal activities such as anti-money laundering and terrorist financing, digital tax evasion, and legal digital currencies provide big data for regulatory technology. Issued before the birth of private digital currencies, the central bank can gain the initiative of digital currencies.