The four magic weapons for the central bank to deal with speculators in the foreign exchange market are: 1) buying and selling local currency, US dollar or other currencies directly in the foreign exchange market; 2) Raise the local currency interest rate; 3) Tightening local currency credit to prevent local currency outflow; 4) Issue relevant statements. Through the above measures, central banks have greatly increased the financing cost of speculators in the foreign exchange market, forced them to stop losses and close their positions, and returned the exchange rate to a reasonable level. The above four methods, especially the short-term effect of the central bank's intervention in the foreign exchange market, are the most obvious, which is often the reason for the sharp fluctuation of the exchange rate.