If the supply of foreign exchange exceeds the demand, the foreign exchange rate will rise and the local currency will depreciate.
Let's just say that foreign exchange is just like ordinary commodities. If the supply of foreign exchange exceeds the demand, the price will definitely rise. Take the US dollar as an example. The exchange rate of foreign exchange was originally 1 US dollar =7 RMB. At present, the supply of US dollars exceeds demand, the price of US dollars rises, the foreign currency US dollars appreciate, and the local currency RMB depreciates. So $ 1 can now be exchanged for more RMB, that is, $ 1 =7.5 RMB, which means that the foreign exchange rate rises and the local currency RMB depreciates.