The recovery of the world economy has been slow since the global financial crisis in 2008. Not only has trade protectionism been on the rise globally, but also emerging trade conflicts among major economies have occurred. China, as the second-largest economy in the world, has been plagued by trade conflicts, slow industrial upgrading, and gloomy economic growth. To promote regional economic cooperation, China proposed the "Belt and Road Initiative" strategy in 2013 to boost China's outward foreign direct investment and trade with the countries along the route, promoting the economic development of both China and BRI countries. This thesis collects and analyzes the data of China's outward foreign direct investment and trade with the major BRI countries from 2005 to 2019, and describes China's major investment destinations, as well as China's major trading partners and commodities, then analyzes both trade volume effect and trade structure effect of China's OFDI on the home country.First of all, by referring to the relevant literature of OFDI and its trade effects, the analytical framework of this paper is established. In terms of the trade volume effect, this paper divides China's OFDI into two categories: Path-wise OFDI and Inverse OFDI on account of GDP per capita in investment destinations. It studies the influence of both Path-wise investment and Inverse investment on the volume of export and import. Then, by using SITC Code to measure China's import and export structure, and the effects of China's OFDI on the export and import of resource-intensive products, capital-intensive products, and labor-intensive products are studied respectively. Panel data from 2005 to 2019 in China and 55 representative BRI countries is utilized for empirical study using Gravity Model. The study finds that both Path-wise OFDI and Inverse OFDI has positively contributed to both China's export and import volume. As for trade structure, China’s OFDI has promoted the upgrading of China's export structure, which is shown by the decrease of export of resource-intensive and labor-intensive products, and the increase of export of capital-intensive products. However, China's OFDI does not exert a significant influence on China's import structure, it only results in an increase in the import of labor-intensive products. Finally, the paper summarizes the results of the study, points out the limitations of the paper and puts forward specific policy recommendations for China to promote investment and trade in BRI countries.