The function of foreign exchange reserves in a country's financial system is mainly "buffering". Adequate foreign exchange reserves show a country's ability to intervene in the foreign exchange market and maintain the exchange rate, which has a certain effect on stabilizing the exchange rate; However, if a country's foreign exchange reserves are too large, it will often inhibit economic growth. Therefore, China should maintain a moderate scale of foreign exchange reserves. This paper analyzes the importance of moderate foreign exchange reserve scale in detail, and makes a more comprehensive description of the research status of moderate foreign exchange reserve scale in China at present. Keywords: international reserves, foreign exchange reserves, moderate scale, China management and use