Natural biological CO2 fixation converts atmospheric CO2 to energy-dense carbohydrates, thereby providing an alternative to fossil fuels and contributing to the restoration of carbon balance. Recent advancements in the mechanisms of biological CO2 fixation have led to innovative architectures of CO2 fixation pathways and energy systems that exceed the efficiency of natural carbon assimilation. Synthetic CO2 bioconversion systems (SCBS) have been designed and reprogrammed for the carbon-neutral or carbon-negative biomanufacturing of chemicals from CO2 by integrating multi-carbon biosynthesis with various energy conversion methods, including light, electrical, and chemical processes. In this review, we systematically analyze how to achieve efficient matching of CO2 fixation modules with energy supply modules, aiming to establish scalable SCBS for addressing the pressing issue of atmospheric CO2 overload. Then, we propose a systematic framework for designing next-generation biomanufacturing with enzymatic or microbial CO2 bioconversion systems, facilitating the construction and optimization of SCBS towards carbon-neutral or carbon-negative bioproduction. Furthermore, we emphasize transformative SCBS technologies, such as photo-biohybrid systems for converting light into chemical energy, electro-biohybrid systems for transducing electrical energy into chemical forms, and enzyme cascade systems for repurposing chemical energy, all of which aim to achieve unprecedented efficiency in powering biosynthesis from CO2. Finally, we propose a strategic roadmap for carbon-negative biomanufacturing ecosystems, wherein bioinspired CO2 fixation platforms can synergistically integrate with the principles of a circular economy to facilitate the industrial transition to net-zero emissions.