Abstract: In recent years, the quantity and intensity of China's aquatic products import have been increasing gradually, and the RMB exchange rate fluctuation has increasingly highlighted its restriction. The influence of RMB exchange rate pass-through on the price of domestic aquatic products will surely attract the attention of people in large countries of aquatic products. Therefore, this paper focused on the mechanism of the impact of exchange rate fluctuations on prices and studied the impact of RMB nominal exchange rate level and its volatility on the import price of aquatic products in China from theoretical and empirical perspectives. In this paper, the theoretical model analysis under the background of small open economy was constructed, and the results showed that: the appreciation of the RMB would encourage aquatic product imports; the risk of RMB exchange rate was negatively correlated with the price of aquatic products. That is to say, if other conditions remained unchanged, the lower the risk of exchange rate fluctuations was and the lower the exchange rate risk was, the higher the price of aquatic products importers were willing to bear. At the same time, for the convenience of research, this paper focused on the level of domestic nominal exchange rate that affected the import price index of aquatic products and its fluctuation risk. This paper adopted the monthly data of import prices of aquatic products from January 2005 to December 2019 to build an empirical model of aquatic product prices. Through empirical analysis, the combined net effect of the two variables of RMB nominal exchange rate and exchange rate fluctuation risk was -0.004 5, which meant that the pass-through effect of exchange rate on aquatic product import price was still incomplete. Although the RMB foreign exchange market had been improved, the risk bearing capacity and transference capacity of Chinese importers of exchange rate volatility were relatively weak, because the choice of hedging tools was relatively limited. Among the factors affecting import prices, the cumulative elastic ranking of the lagging performance coefficient of each factor could be seen (table 4): the nominal effective exchange rate of RMB had a great influence on the import price of aquatic products, accounting for 84.2%, ranking the first. The second risk of exchange rate volatility was 3.9%, which was basically the same as the domestic competition (3.4%). Domestic demand for imports came in fourth, followed by a smaller impact on exporters' costs, at 0.8%. In the economic sense, the more domestic consumers consume aquatic products, the more obvious the trend of import price decline. From the perspective of national market of aquatic products, compared with developed countries, the market structure of aquatic products in China was not perfect, and the results of theoretical analysis were consistent with the results of VAR and ECM empirical tests. In addition, the appreciation of RMB will stimulate the import of aquatic products, which will reduce the import price of aquatic products to some extent. Through the continuous improvement of China's exchange rate market, it can provide empirical support for China to implement a more flexible exchange rate system reform.