In the contemporary context where the digital economy is reshaping the global development landscape, exploring its inner mechanism in enabling common prosperity carries significant theoretical value. Integrating the classical analytical paradigm of Marxist political economy with the grounded theory research method, this study systematically analyzes 101 core journal articles from the CNKI database spanning the years 2021 to 2025. Moving beyond the limitations of singlediscipline research, a dynamic theoretical model of “motivation–adjustment–outcome” is constructed through a threestage coding process. This model reveals the inner mechanism by which the digital economy empowers common prosperity and expands the disciplinary boundaries of research on the relationship between the digital economy and common prosperity. The study demonstrates that the productive forces form the foundational driving force through digital technological innovation, the relations of production undergo coordinated dynamic adaptation via digital technology, and the superstructure provides institutional safeguards supported by digital technology. The threedimensional interaction among these factors collectively promotes the realization of common prosperity.