With the continuous expansion of China's OFDI scale, the impact of China's OFDI on RMB internationalization has also attracted much attention. In this paper, we systematically examine the impact of OFDI on RMB internationalization from the perspectives of qualitative analysis and quantitative analysis. The qualitative analyoursis of the mechanism of action shows that OFDI promotes RMB internationalization mainly through direct and indirect mechanisms. Furthermore, we perform a quantitative empirical analysis using the macro monthly data of 96 months from 2011 to 2018, and the results show that OFDI can indeed significantly promote RMB internationalization in China. Finally, according to the research conclusions of this paper, we put forward some suggestions on how to better promote RMB internationalization by OFDI.