The study of the impact of environmental regulations on green patent output has become a hot topic in academic research. The dual externalities in this impact process need to be addressed through the joint efforts of environmental regulations and intellectual property protection. Integrating environmental regulations，green patents，and intellectual property protection into a unified analytical framework is significant for exploring the effective solutions to environmental problems. This paper used the data from 11 provincial-level regions in the Yangtze River Economic Belt from 2010 to 2021 to examine the impact of environmental regulations on green patent output，and further analysed the moderating effect of intellectual property protection. The research found that： （1） there is a U-shaped relationship between environmental regulations and the quantity of green patent output；（2） Environmental regulations exhibit complex nonlinear characteristics on the quality of green patent output，and after crossing the inflection point of the U-shaped relationship，they can effectively improve the quality of green patent output；and （3） Intellectual property protection plays a significant positive regulatory role in the environmental regulation process affecting the quantity and quality of green patent output. This study has filled the gap in theoretical research on the impact of environmental regulations on green patent output，and will provide practical insights for balancing environmental protection and economic development in the Yangtze River Economic Belt.