Using the panel data of 274 cities from 2011 to 2019, this article studied the impact of the digital economy on the low-carbon transformation and space overflow effect on the city’s low-carbon transformation and used the panel threshold model to calculate the regulatory effect of public attention. Studies found the following: (1) The digital economy, the urban low-carbon transformation level, and public attention show regional differences, manifesting as the distribution of "point clusters" and "decreasing from east to west", and as far as the speed of change, after the year 2015, the annual increase of various indicators increased. (2) The role of digital economy development and urban low-carbon transformation levels have a "U" relationship. At present, most cities across the country have passed the point of inflection, which presents a significant promotion effect. However, in a comparison of regional coefficients, the Eastern region > Western region > Midlands. (3) The development of the digital economy has a significant “siphon effect” on the impact of urban low-carbon transformation. (4) With the increase in public attention in the region, the positive promotion of the digital economy on the urban low-carbon transformation has gradually increased.

Consumption-oriented or efficiency-oriented, it is a hard choice for the green technology innovation pathway. This paper uses the intermediary model to empirically analyze the panel data from 250 prefecture-level cities in China from 2010 to 2019. The conclusions show that: 1. At present, energy consumption-oriented green technology innovation at the national level in China shows a completely intermediary effect, which has a more obvious emission reduction effect; compared with energy consumption, energy efficiency-oriented green technology innovation only has a very weak intermediary effect of 6.58%. 2. Only the Eastern non-resource cities and the Midwest resource cities’ green technology innovation have the effect of energy efficiency-oriented emission reduction, accounting for 8.11% and 9.02%, respectively. 3. Both the Eastern resource cities and the Midwest non-resource cities have no intermediary effect on energy efficiency, so carbon emission reduction is more difficult than in other cities.