From 1996 to now, China's foreign exchange system has been extended to the exchange rate system pegged to the US dollar, that is, based on the supply and demand of the US dollar and RMB, the exchange rate of RMB against the US dollar is controlled in a fixed range. This is because China and the United States have the most trade exchanges, and maintaining the stability of the exchange rate of RMB against the US dollar is beneficial to the production and operation of foreign trade enterprises. In China, where the financial market is not very mature, a large floating exchange rate system will make foreign trade enterprises bear great risks. For example, the rise of exchange rate will only make export enterprises exchange a small amount of foreign currency for RMB, which will make enterprises lose money. Under this exchange rate system, the exchange rate between RMB and other countries is the arbitrage exchange rate. First, calculate the dollar value of a foreign currency, and then multiply it by the number of RMB in one dollar to get the exchange rate of RMB against that country. Due to the subprime mortgage crisis in the United States, the demand of the United States for China's export products has changed, and China needs to change the current exchange rate system. According to the recent report, it should be a managed floating exchange rate system based on market supply and demand and referring to a basket of currencies.