The role of banks: 1 is the link to raise and allocate funds for the development of national production; 2. Banks can master and reflect the information of social and economic activities, and provide necessary basis for enterprises and countries to make correct economic decisions; 3. Banks supervise and manage the production and business activities of various ministries and enterprises of the national economy, so as to optimize the industrial structure and improve economic benefits. Why should China maintain the basic stability of RMB benchmark interest rate and exchange rate at present? First of all, why should we keep the benchmark interest rate of RMB stable? Because the bank is an important macro-control tool of the country, and the interest rate of the bank is an important part of it. Keeping the interest rate stable can maintain the stable growth of the national economy and the stable amount of RMB in society, thus stabilizing the currency and preventing inflation or deflation. Why keep the exchange rate stable? The so-called exchange rate is the exchange rate between two currencies, and the rise of foreign exchange rate means the depreciation of the local currency, which will make imports exceed exports and put the national industries of importing countries at a disadvantage. On the contrary, there will be a surplus, which is beneficial to exporting countries, but maintaining a high level of surplus will occupy a large number of foreign markets, cause dissatisfaction in the international market (the Opium War is an example), and it is more likely to be dumped by the defendant and punished by the WTO. Therefore, maintaining exchange rate stability is a long-term strategy for economic development.