<p>Sn-based solders enhanced with nanoparticles have garnered extensive attention in recent years due to their excellent properties. The doping of various nanomaterials offers endless possibilities for the development of these composite solders. This review focuses on reviewing the properties and reliability of nanoparticle-enhanced Sn-based solder interconnects in recent years, introducing the concept and material types of nano-enhanced solders, and systematically examining the impact of various nano-reinforcement particles on solder joint performance, with corresponding mechanisms proposed for different situations. Additionally, it comprehensively considers the effects of different reliability tests on joint performance, with comparisons and analyses conducted. Finally, scientific challenges, limitations, and potential future breakthroughs in composite solder joints are proposed based on the current research. This review aims to provide comprehensive theoretical guidance for the future of composite soldering, enhancing the potential for industrial applications.</p>