Raising the foreign exchange risk reserve ratio has two effects on the exchange rate: first, it sends a signal that the policy will further stabilize the exchange rate and guide market expectations; Second, it increases the cost of the bank's forward foreign exchange sales business, forces the bank to raise the forward foreign exchange sales price, inhibits the foreign exchange demand of enterprises, and then affects the spot exchange rate. Since the establishment of 20 15, the foreign exchange risk reserve ratio has been adjusted four times. There are two upward adjustments, which occurred in the depreciation periods of 20 15, 10 and 20 18 respectively. Both were downward adjustments, which occurred in the appreciation cycles of September 20 17 and June 2020+00 respectively. In the short term, the policy has played a role in stabilizing the exchange rate; In the long run, there is a certain inertia in the exchange rate under the established trend, which still depends on the internal and external fundamentals of the cycle.