China implements the foreign exchange settlement and sale system, that is, the foreign exchange obtained by enterprises must be sold to foreign exchange settlement banks (such as Industrial and Commercial Bank of China and Bank of China), and the surplus foreign exchange positions obtained by foreign exchange settlement banks are sold to the central bank (RMB Bank of China), forming China's national foreign exchange reserves, and the central bank buys foreign exchange from commercial banks in RMB. In other words, foreign exchange reserves are obtained by issuing RMB, and the RMB so issued is also foreign exchange, resulting in an increase in the base currency.