Due to their low greenhouse effect and exceptional insulating properties, C4F7N-CO2 gas mixtures have garnered significant attention. In particular, understanding the decomposition characteristics of C4F7N-CO2 is crucial for their practical use as an eco-friendly dielectric medium. At elevated temperatures, the pyrolysis of C4F7N produces high concentrations of CFN, CF3, and C2F2, along with lower levels of C3F5, C4F6N, C2F, and CN. A further increase in temperature may lead to the decomposition of CO2 into CO and additional components such as C-2, C2F3, C3F4, C4F7 and C3F6, CF, CO, C3F7, C3F2, C3F, C3F3, C3F3N, C-3, CF2, and CF2N. Under electrical discharge conditions, the decomposition of CO2 becomes more pronounced, forming products like CO, C2O, O-2, C2O2, and C2O4, with up to 25 decomposition components observed. These include products originated from both C4F7N and CO2 and their combinations. In ultra-high electric field intensities, only small molecules such as O-2, C-2, C-3, and N-2 are detected among the decomposition products. This study aims to provide theoretical insights and valuable data to advance research into the decomposition behavior and practical engineering applications of C4F7N-CO2 gas mixtures under extreme conditions.