Currently, China is at a critical juncture for achieving high-quality economic development, and the goals of carbon peaking and carbon neutrality pose new challenges to this endeavor. Therefore, based on panel data from 284 prefecture-level cities in China spanning from 2011 to 2021, this study employs various econometric methods and considers green technological innovation as a mediating variable to empirically examine the impact of carbon emissions on high-quality economic development and its underlying mechanisms. The results indicate that there exists a non-linear, inverted “U-shaped” relationship between carbon emission intensity and high-quality economic development. As carbon emission intensity increases, its role transitions from promoting high-quality economic development to inhibiting it. Furthermore, both carbon emission intensity and high-quality economic development exhibit significant spatial positive correlations and spatial spillover effects. The local area’s carbon emission intensity also affects the high-quality economic development of neighboring regions. Green technological innovation serves as a mediator, implying that carbon emission intensity can influence high-quality economic development through its impact on fostering green technological innovation. This study holds significant theoretical and practical implications in aiding the implementation of China’s carbon reduction policies and fostering high-quality economic development across various cities.