Asphalt pavement, as an important component of highway construction, its low-carbon transformation is crucial for the construction of green highways. To quantify the environmental impact of asphalt pavement construction and predict the emission reduction potential under the electrification scenario, this study takes the construction of a certain expressway in Guangxi as an example, proposes a comprehensive framework combining life cycle assessment and LEAP, and incorporates the uncertainty of environmental impact assessment results into this framework. The results show that the material production stage is a key influencing stage for global warming, terrestrial acidification and ozone formation. Among them, cement and crushed stone are the main contributing materials, while the environmental impact contribution during the transportation and construction stages is relatively low. The uncertainty results of the three environmental impact indicators are consistent with the certainty results, and the uncertainty level of global warming is the lowest. Under the electrification scenario, the carbon emissions of asphalt pavement construction show a decreasing trend year by year and are significantly lower than those in the benchmark scenario. The electrification transformation of construction machinery, as an emission reduction measure, has significant emission reduction benefits. The research results provide an important scientific basis for promoting the construction of green highways.