With the increasing demand for power density in new energy vehicles and high-power electrical conversion applications, silicon carbide (SiC) power modules are often subjected to extremely high currents and frequent switching operations. The substantial heat generated may lead to system failures, making the investigation of the thermal performance of SiC power modules critically important. This study explores the influence of different fin shapes and fin spacing ratios on the thermal performance of SiC power modules through coupled thermal-fluid simulation and experimental investigations. The results indicate that a droplet-shaped fin configuration offers superior thermal performance compared to other fin shapes, and there exists an optimal fin spacing ratio that maximizes the heat dissipation capability of the SiC power module. This research provides a foundation for the design of heat sinks for SiC power modules in new energy vehicle applications.