Market-based environmental regulations in China, like SO2 and carbon emission trading, were studied to see if they help promote green technology innovation. The study looked at patent data from 278 cities in China from 2003 to 2017. The findings show that SO2 emission trading successfully encouraged green technology innovation, but carbon emission trading did not. The combination of these policies also did not lead to more innovation. The positive impact of SO2 emission trading was mainly seen in the eastern region of China, and it improved the quality of green technology patents. This research suggests that not all market-based environmental regulations can boost innovation, and repeated similar policies may not be effective in stimulating new technology.