Using bilateral trade data between China and 55 countries along the B & R from 2003 to 2016, based on the expanded trade gravitation model, this paper makes an empirical analysis on the impact of China’s foreign direct investment on China’s import and export trade along the B & R from the total sample and the sub sample level.The results of the study indicate that on the overall level, foreign direct investment can promote China’s import and export trade with countries along the B & R;At the sample level, foreign direct investment can promote China’s import and export trade with other countries along the B & R, but, to a certain extent, it will replace the export trade between China and the three economies of ASEAN, India and Russia.Accordingly, under the current situation of increasing trade friction between China and the United States, targeted investment in countries along “The Belt and Road” is of great significance for accelerating China’s “going out” pace and implementing “The Belt and Road” initiative.