This paper measures and analyzes the spatial pattern of green technology innovation efficiency of 110 cities of the Yangtze River Economic Belt in 2017 by using the EBM model. This paper further explores the efficiency's internal driving mechanism with the spatial Durbin model. The results show several findings. Firstly, the efficiency is ahead of the national average level, but there are significant differences between the upper, middle and lower reaches. Secondly, economic development, government support and industrial structure upgrading are the leading forces to directly enhance the green technology innovation capability of the cities. Thirdly, environmental regulation, foreign investment, advanced industrial organization and enterprise benefit have strong spatial spillover effect on the efficiency. To further enhance the green technology innovation capability of cities in the Yangtze River Economic Belt, it is necessary to accelerate the process of regional green innovation's coordinated development, increase government support for green innovation, optimize environmental governance model, promote industrial structure's greenization and upgradation, and enhance the initiative of enterprises' green technology innovation.