For China's urban industrial layout and green development, determining which types of agglomeration externalities are most advantageous to the rise of green total-factor productivity has both theoretical and practical relevance. This research experimentally studies the effects of three types of agglomeration externalities on urban green total-factor productivity using the data of 285 Chinese cities from 2003 to 2018. The findings demonstrate that urban green total-factor output is rising, albeit with certain differences during different time periods. Both the Jacobs externality and the Porter externality are favorable for increasing urban green total-factor production when all cities are evaluated together, although the latter has a stronger promoting influence. The effect of the Marshall-Arrow-Romer externality, on the other hand, is not significant. Furthermore, these effects also depend on the stage of economic development and population size.