Since the proposal of the “Belt and Road” initiative (BRI) in 2013, China’s renewable energy investments in the countries along the route have shown rapid growth and diversification. These investments have shifted from initial product exports and engineering contracts to deeper equity investments and financing cooperation. They not only promote a global energy structure transformation towards green and low-carbon development but also bring significant economic growth and social progress to the participating countries. This study aims to systematically review the research status and trends of renewable energy investments in “Belt and Road” countries through comprehensive bibliometric analysis. Utilizing the Web of Science database and VOS viewer 1.6.17 software for visualization, this research reveals the publication trends, high-impact articles, institutional collaborations, and author networks in this field. Additionally, through keyword co-occurrence network analysis, three core research themes are identified: investment motivations, synergy effects, renewable energy consumption, and international cooperation. This systematic bibliometric analysis not only outlines the current research landscape but also provides important insights for identifying emerging research directions, thereby supporting more in-depth investigations into renewable energy investments within the “Belt and Road” initiative.