Based on the data of China’s direct investment and trade in five South Pacific island countries from 2009 to 2017， with the aid of a gravity model， this paper empirically analyzes the impact of China’s direct investment in five South Pacific island countries on their import and export trade. The empirical results show that the stock and flow of China’s direct investment to these five South Pacific island countries are positively correlated with their trade volume， that is， China’s direct investment in the five South Pacific island countries has an obvious trade creation effect， and the stock of direct investment has a more significant trade effect than the flow of direct investment. But at the same time， the research also found that the trade creation effect of direct investment has a certain time lag. Therefore， we should optimize China’s direct investment in South Pacific island countries in time to enhance the promotion effect of China’s direct investment on bilateral trade， so as to better enhance the winwin effect of China and South Pacific island countries.