Traditional model-based systems engineering (MBSE) methods for complex product design often rely on multiple modeling and simulation tools, complicating system modifications and diminishing design efficiency. In contrast, the emerging X Language, an advanced integrated modeling and simulation language tailored for complex systems, has been successfully applied to the satellite energy system. This approach involves analyzing the satellite’s power supply states in different zones, leveraging the XLab platform, which supports X Language, to create system-level and physical-level models, and using the X Language simulator to conduct simulation verification. This holistic design strategy offers a streamlined and efficient solution for integrating and optimizing multidisciplinary and multi-software complex products.