To cope with the increasingly serious global warming and implement China’s carbon peak and carbon neutrality goals, the promotion of energy conservation and emission reduction in the construction industry should be accelerated. Starting with the foundation treatment project in road engineering, this study used the carbon emission factor method. According to the budget consumption quota of the project, the carbon emissions of each sub-project in the project were calculated. Then, the cost of each sub-project was calculated based on the engineering cost standard. From the perspectives of carbon emissions and engineering costs, data analysis was conducted to explore the project’s emission reduction potential. The results indicate that materials are the primary source of carbon emissions in foundation reinforcement projects, mainly from high carbon emitting materials such as cement and steel bars. For sub-projects, the proportion of emissions from compacted pile engineering is the highest (72.6%). By comparing the relationship between costs and carbon emissions, it is found that the ratio of engineering costs to carbon emissions of replacing sand, stone chips, and crushed stone projects is the highest. To economically and efficiently control carbon emissions in foundation reinforcement projects, priority can be given to sub-projects with a low ratio of engineering costs to carbon emissions and low carbon emissions, such as compacted pile engineering, replacement soil engineering, and cement stabilized soil engineering. The proposed energy conservation and emission reduction measures based on the analysis results can provide method references and data support for carbon emission accounting in road engineering.