Urban green transformation is an important part of global low-carbon development. Coercive government policies are critical to achieving success, but, as of now, there is no unified concept of “green competitiveness”. To address climate change, it is necessary to clearly define core concepts and apply measures. For this study, “urban green competitiveness” refers to the continuous improvement of total factor productivity by cities while fully emphasizing resource limitations and environmental issues to achieve economic growth. This article focuses on a Chinese policy of “dual control of the amount and intensity of energy consumption” (DCEC), which has not been fully studied. The DCEC policy incorporates a quasi-natural experiment to assess whether urban green competitiveness has been affected. This paper builds on the multi-period DID model and explores the effect based on city-level data from 2003 to 2019. The conclusion shows that DCEC policy can address climate change by restricting energy consumption and intensity. Success is achieved through the promotion of local green patent innovation and by intensifying environmental regulation. The policy should start from a long-term perspective by promoting structural and technological changes in the economy, rather than short-term quick success and instant benefits.