Solve the persistent long-term balance of payments. After all, a country's reserves are limited, and a long-term deficit will inevitably exhaust a country's international reserves, making it difficult to achieve the final policy buffer. The foreign exchange buffer policy has limited effect and cannot be used to solve the persistent balance of payments deficit, especially when the instability of a country's currency makes people's confidence in the country's currency shake, which leads to large-scale capital flight, and it is even more difficult to achieve the expected effect.