On July 21st of 2005, China government announces to abandon the exchange rate system the RMB pegged to US dollar which has been valid for 11 years. Since this reform of exchange rate, the more flexible exchange range policy has increased the exchange risk of both the government and companies. Therefore, it has been extremely urgent to establish a novel exchange management and risk control system that is fit for current situation of China. VAR model is a quantitative tool that meets our demand. VAR estimated the maximum possible loss of an investment set in a certain coming period based on a certain probability. By utilizing VAR methods, we can measure the risk more precisely. VAR is a general approach to measure risks, which can be used to measure the marketing risk, credit risk and so on. This paper adopts a combination of empirical research and theoretical research, introduces the basic concept of foreign exchange risk, it includes the causes and classification of foreign exchange risk and the traditional methods of foreign exchange risk measurement. But it focuses on the VAR method of foreign exchange risk measurement. This paper selects 3 VAR methods (HS, MC and GARCH model) to measure foreign exchange risk, calculate the VAR value of RMB against US dollar and RMB against Euro respectively, the data is from January 2017 to December 2020. From the comparison of the measurement results of three VAR methods, it is concluded that the best measurement method is the GARCH model to estimate VAR.In short, combined with the literature and the empirical research of this paper, it plays a good guiding role for the future systematic analysis and measurement of foreign exchange risk in microeconomics.