In recent years, China's economy has experienced a rapid transformation period from rugged economic development to a sustainable economic development style. Increasing green total factor productivity (GTFP) is considered as one of the important signs. The application of innovation capability (ICY) is becoming more and more widely used in modern life. But it is still unclear how ICY can affect GTFP. With increasingly stricter environmental laws and regulations, how environmental regulations (ER) affect GTFP is unclear. This research contributes to the literature on the impact mechanisms of ICY and ER on GTFP using the data on 30 Chinese provinces covering the period from 2006-2017. The results indicate both ICY and ER can effectively promote GTFP. Compared with ER, ICY has obvious heterogeneity on GTFP, that is, the stronger the ICY is, the stronger it promoting effect on GTFP. Next, ICY plays an intermediary role in ER and GTFP, and ER can promote GTFP through ICY. Accordingly, the paper puts forward some policy suggestions, such as optimizing and improving ER policy, unswervingly practicing innovation-driven development strategy, strengthening monitoring and supervision.