The use of foreign exchange derivatives to manage foreign exchange risk is a double- edged sword. If it can be used properly, it can not only reduce the foreign exchange risk of enterprises, but also save transaction costs. If used improperly, it may induce greater exposure to foreign exchange risk and cause more serious economic losses. This study focuses on the relationship between foreign exchange risk hedging and firm value, using data of 10,915 listed non-financial companies in China's main board market from 1804 firms from 2007 to 2021. The relationship between foreign exchange risk hedging and firm value is demonstrated by benchmark regression, mediation effect tests, moderating effect tests, heterogeneity tests, robustness tests and endogeneity tests. The results show that: (1) Foreign exchange risk hedging still significantly increases the enterprise value of non-financial listed companies in China's main board market, and the improvement is 11.5% per year (2) Foreign exchange risk hedging will increase the enterprise value of non-financial listed companies in China's main board market by reducing cash flow risk; (3) Company size has a negative moderating effect on the relationship between foreign exchange risk hedging and enterprise value. Smaller enterprises are more likely to hedge and avoid tax risks, and the cost of financial distress is lower. Foreign exchange risk hedging has a more positive impact on enterprise value. (4) Nature of stock rights has a negative moderating effect on the relationship between foreign exchange risk hedging and enterprise value. Compared with non-state-owned enterprises, state-owned enterprises are subject to more supervision when conducting foreign exchange derivatives transactions. Compared with state-owned enterprises, non-state-owned enterprises' foreign exchange risk hedging has a greater positive impact on enterprise value than state-owned enterprises. (5) Overseas income has a positive moderating effect on the relationship between foreign exchange risk hedging and enterprise value. Because multinational enterprises are more prone to financial risk impact, the positive impact of foreign exchange risk hedging on enterprise value of multinational enterprises is greater than that of non-multinational enterprises. (6) Different regions have different levels of economic development and opening to the outside world. Compared with central and western China, enterprises in eastern China use foreign exchange risk hedging to have a significantly greater positive impact on enterprise value than those in central and western China; For western China, the impact of foreign exchange risk hedging on enterprise value is not significant; (7) During 2012-2015, foreign exchange risk hedging had the greatest impact on enterprise value, while before 2012, foreign exchange risk hedging had the least impact on enterprise value.