Green technology innovation plays a pivotal role in supporting low-carbon development and serves as a key driver for enhancing carbon reduction maturity. Using a specialized calculation model, this study calculates the Carbon Reduction Maturity Index for 30 Chinese provinces from 2003 to 2022. The empirical analysis, based on a fixed-effects panel model and a mediation effect model, reveals that a 1% increase in green technology innovation leads to an estimated 0.85% rise in carbon reduction maturity. Additionally, spatial spillover effects indicate that advancements in one province contribute to a 0.27% increase in the carbon reduction maturity of neighboring regions. The mediation analysis confirms that industrial structure upgrading and energy structure optimization play significant roles in this process, explaining 21.8% and 18.4% of the total effect, respectively. Heterogeneity analysis shows that the impact of green technology innovation is more pronounced in economically developed eastern regions, where market-driven mechanisms and technological advancements accelerate the transition to a low-carbon economy. Based on these findings, the study proposes targeted policy recommendations, including regionally differentiated green technology innovation strategies, industrial structure optimization, energy efficiency improvements, strengthened international cooperation, and the promotion of green consumption to enhance green innovation capabilities and advance carbon reduction maturity.