One of the ways for the central bank to intervene in the foreign exchange market usually refers to a means for the People's Bank of China to buy and sell foreign exchange in the foreign exchange market, thus changing the money supply in the domestic market and adjusting the exchange rate. The other is sterilization intervention, that is, the monetary authorities use other monetary policy tools (such as the open market business in the national debt market) to offset the influence of foreign exchange transactions on the money supply by the monetary authorities, so as to keep the money supply unchanged. The central bank's intervention in the foreign exchange market is not continuous. In order to prevent the suboptimal Nash equilibrium solution, the central bank will try its best to prevent private speculators from knowing their exact objective function. The central bank's weight on exchange rate stability depends on the central bank's judgment on the exchange rate trend. If a large number of private investors think that it is impossible for the central bank to intervene in the future exchange rate, although the exchange rate level may be inconsistent with the expectations of the central bank, it is less likely for the central bank to reverse market sentiment. In this case, the loss of central bank intervention will be great. At this time, the central bank's exchange rate policy may be adjusted with the social and political pressure at home and abroad.