Abstract: Exploring how green technology innovation drives the green and low-carbon circular development of the Yangtze River Delta is conducive to accelerating the realization of the high-quality integrated development goal of the Yangtze River Delta. Based on the multi-dimensional index system and principal component analysis method, the green and low-carbon circular development index of 41 cities in the Yangtze River Delta was measured. The generalized least square method, spatial panel and threshold model were used to empirically test the driving mechanism and effect of green technology innovation on the green and low-carbon circular development of the Yangtze River Delta. The findings were as follows: (1) From the perspective of benchmark regression, green technology innovation significantly promoted the green and low-carbon circular development of the Yangtze River Delta, and there was regional heterogeneity. The upgrading of industrial structure, government competition and human capital played a positive moderating role in the impact of green technology innovation on the green and low-carbon circular development. (2) From the perspective of spatial effect, green technology innovation had positive spatial correlation and spatial spillover effect on the green and low-carbon circular development. (3) From the perspective of threshold effect, with the improvement of the financial development, the promoting role of green technology innovation on the green and low-carbon circular development of the Yangtze River Delta was constantly enhanced. The above conclusions had important policy implications for accelerating the green and low-carbon circular development and integration process of the Yangtze River Delta.