With the intensification of global climate change and the increasing prominence of environmental issues, China's economy is facing huge challenges in transforming from the traditional carbon-based technological path to a green and low-carbon economy. How to effectively break this “carbon lock-in” and achieve “carbon unlocking” has become an important topic for the sustainable development of China's and even the global economy. Based on the data of 279 prefecture-level and above cities in China from 2011 to 2022, this paper empirically examines the impact of the integration of digital technology and intelligence on “carbon unlocking”. The empirical results show that: (1) The development of the integration of digital technology and intelligence is conducive to promoting “carbon unlocking”, and this promoting effect is more prominent in non-resource-based cities and non-old industrial base cities. From different dimensions of “carbon unlocking”, the promoting degrees of the development of the integration of digital technology and intelligence are, from high to low, the technological dimension, the institutional dimension, the industrial dimension and the cultural dimension. (2) The mechanism test shows that the integration of digital technology and intelligence can promote “carbon unlocking” by improving the level of market integration. (3) Further research finds that policy support for the hard environment, such as the construction of new digital infrastructure and the implementation of the “Broadband China” strategy, as well as policy support for the soft environment, such as the marketization of data elements and the opening of public data, can help enhance the promoting effect of the integration of digital technology and intelligence on “carbon unlocking”. This study aims to deeply explore how the integration of digital technology and intelligence promotes “carbon unlocking” by influencing market integration, in order to provide a new perspective and theoretical support for the green and low-carbon transformation of China's economy and the achievement of the “dual carbon” goals.