This paper proposes a slacks‐based global DEA for Chinese urban green economic growth (GECO) and a global Malmquist index for decomposing its changes into three components, technology change (GTEC), scale efficiency change (GSEC), and pure technical efficiency change (GPEC). On this basis, using China's 286 city‐level panel data for the period 2006–2018, this paper then analyses the key driving factors of GECO and the regional heterogeneous effects of resource abundance on GECO. Results show that: (a) during the sample period, the city‐level GECO of China remains at a low level. GTEC and GSEC promote GECO, but much of this growth effect is offset by a reduction in GPEC; (b) there is negative effect of resource abundance on Chinese urban GECO. Specifically, in eastern, central, and western cities, the negative effect on GECO by adversely affecting GSEC and GPEC, while in northeast cities, the main transmission is GTEC; (c) because the key factors which affect the decompositions show different characteristics from regional heterogeneity perspective, this paper takes further step to formulate specific strategies and effective implementation of policies for the improvement of GECO in China's city level.