Abstract: Scientific and technological innovation is essential for the sustainable development of a low-carbon economy. To explore the potential impact of scientific and technological innovation on carbon emissions, measures the comprehensive scientific and technological innovation level of each province in China from 2002 to 2019. On this basis, the panel quantile model is used to analyze the heterogeneity characteristics of the impact of comprehensive scientific and technological innovation and different types of scientific and technological innovation entities（industry enterprises, universities, and scientific research institutions） on regional carbon emissions. At the same time, a mediation effect model is used to identify the indirect impact of scientific and technological innovation on carbon emissions. The results show that the impact of scientific and technological innovation on carbon emissions presents an inverted U-shaped structure and has a significant inhibitory effect. The scientific and technological innovation of industry enterprises and universities has the most potent inhibitory effect on carbon emissions in the 75% quantile, and the scientific and technological innovation of scientific research institutions has the most potent inhibitory effect on carbon emissions in the 50% quantile. Scientific and technological innovation can indirectly promote carbon emissions through the urbanization rate, economic growth, investment in industrial pollution control, and investment in fixed assets in the energy industry. However, it can indirectly suppress carbon emissions by adjusting the industrial structure. Moreover, the impact of scientific and technological innovation in different types on carbon emissions are different. These findings will provide broader insights into the low-carbon development of scientific and technological innovation.